Leads to the development of cancer. Main risk factors for malignant tumors and prevention

There are a huge number of risk factors for developing cancer in the modern world, which is why cancer has become so common in the last 50 years.

Risk factors are external causes of cancer, that is, associated with a person’s lifestyle and environment, and not with genetic characteristics.

All of them lead to damage to the DNA structure, which usually results in oncogene activation and the appearance of malignant cells. As a result, cells do not die due to apoptosis, but begin to multiply and divide uncontrollably, forming a malignant tumor.

Conventionally, all external risk factors (causes of cancer) can be divided into groups:

1. Physical factors risk of developing cancer (ultraviolet radiation, ionizing radiation).

Ultraviolet and X-rays cause physical damage to DNA by producing large amounts of free radicals. Many studies have shown that ultraviolet (UV) radiation is carcinogenic to humans and often causes the development of basal cell carcinoma, squamous cell carcinoma, etc. People with white skin are at risk, especially blue-eyed and gray-eyed blondes, people who have a tendency to develop freckles. Also, the risk of skin cancer is high in people with sunburn, multiple moles and dysplastic nevi.

2. Chemical risk factors for cancer development(carcinogenic substances, soil and water pollution with industrial waste).

Chemical carcinogens cause DNA damage by creating chemical bonds. Recently, the problem of soil and water pollution by chemical waste has become an acute problem for our society.

3. Biological factors risk of cancer (HPV/HPV virus, etc.)

Viruses are classified as biological carcinogens. Viruses usually integrate into the DNA structure itself and destroy it. There are 14 very dangerous strains of human papillomaviruses that have demonstrated the ability to cause invasive. For example, Herpes II is one of several factors that interact with HPV to increase the risk of developing cervical cancer.

Also, each type of cancer has its own risk factors, depending on the location of the tumor and its clinical characteristics.

Risk factors for developing breast cancer:

The woman is over 50 years old;

Having close relatives (mother, sister, grandmother) with breast cancer;

The presence of precancerous breast diseases, such as: atypical fibroadenomatosis, atypical hyperplasia, etc.;

Early onset of the menstrual cycle (before the age of 12 years);

Late onset of menopause (after 55 years);

Absence of pregnancies and the birth of the first child after the age of 30;

Presence of obesity or excess body weight of 2 degrees;

Taking oral hormonal contraceptives;

History of the BRCA1 and BRCA2 genes.

Risk factors for developing lung cancer:

Long-term cigarette smoking, more than 20 years;

Long-term use of vapers (questionable due to insufficient observation time);

Systemic exposure to harmful substances such as radon, asbestos, arsenic, etc.;

A history of tuberculosis or other inflammatory and infectious chronic diseases.

Risk factors for colorectal cancer:

Age over 50 years;

Presence of microsatellite instability;

The presence of adenomatous polyps in the intestines;

The presence of chronic inflammatory bowel diseases;

Presence of obesity or excess body weight;

Lack of physical activity;

Long-term smoking, more than 30 years

Excessive alcohol consumption.

Risk factors for developing cervical cancer:

A large number of sexual partners and promiscuity;
Attitude to a certain ethnic group (African American, Latin American and Indian women are more often affected);
The presence of oncopathogenic human papillomavirus (HPV, HPV), or its presence in a sexual partner;
Prenatal (during the mother's pregnancy) exposure to Diethylstilbestrol (DES);
Presence of HIV infection.

Risk factors for developing endometrial cancer:

The woman's age is over 55 years;
Late menopause (after 55 years);
Late birth of the first child (after 30 years);
Long-term hormonal therapy, without the use of progesterones;
Having a diagnosis of infertility;
Having obesity or excess body weight.

Risk factors for developing ovarian cancer:

The woman is over 50 years old;
The presence of ovarian cancer in close relatives (mother, daughter, sister, grandmother, aunt);
Positive test for the presence of BRCA1 or BRCA2 genes;
A history of hormonal disorders (irregular periods).

Risk factors for prostate cancer:

The man's age is over 60 years;
Presence of human papillomavirus (HPV);
Race belonging to a certain group (African Americans are more likely to get sick);
Chronic inflammatory diseases of the genitourinary system.

Risk factors for developing skin cancer and melanoma:

Excessive exposure to ultraviolet radiation;
Light and sensitive skin phenotype;
A large number of birthmarks;
Tendency to sunburn;
Prolonged exposure to the sun at midday.

SMOKING. Based on an expert assessment of experimental and epidemiological studies of the carcinogenicity of smoking conducted by IARC, it has been proven that smoking is etiologically associated with a number of malignant tumors, namely the lip, tongue, other parts of the oral cavity, oropharynx, hypopharynx, esophagus, pancreas, larynx, trachea, bronchi and lungs, bladder and kidneys. The incidence of these forms of cancer in the Russian Federation is more than 50% of the incidence of all malignant tumors among men. Among women, the percentage of malignant tumors etiologically associated with smoking is much lower and does not exceed 10%.

Along with smoking, excess alcohol consumption plays a role in the etiology of some of the above forms of cancer, namely cancer of the oral cavity, esophagus, pancreas and larynx. The latter factor, being an independent risk factor for the above forms of cancer, enhances the effect of smoking.

The attributable risk of smoking for individual forms of cancer, that is, the percentage of all cases of a given cancer that is etiologically associated with smoking, varies. According to the most conservative estimates, the direct cause of 80-85% of all cases of lung cancer is smoking. Smoking and excessive alcohol consumption are responsible for 80% of lip and oral cavity cancers.75 % esophageal cancer, 30% pancreatic cancer, 85% laryngeal cancer and about 40% bladder cancer.

Quitting smoking will lead to a reduction in the incidence of malignant tumors by 25-30%, which for Russia amounts to 98,117 thousand cases of malignant tumors per year.

NUTRITION. Nutritional components play an important role in the occurrence of a number of forms of malignant tumors. At least one third of all malignant tumors are related to diet.

A number of dietary components, namely animal fats, are likely to increase the risk of colorectal cancer, and possibly breast, uterine, ovarian and prostate cancer. While vitamins, primarily vitamin C, A, beta-carotene, as well as foods rich in these vitamins, reduce the risk of malignant tumors, including oral cancer of the esophagus, stomach, larynx, lung, bladder, colon intestines, and possibly the mammary gland.

In addition, salted, smoked and canned foods may contain various carcinogenic substances, namely N-nitrosoamines and polycyclic aromatic carbohydrates (PAHs). There is reason to believe that nitrosamines, as well as their precursors (nitrates, nitrites) in food, are associated with an increased risk of cancer of the esophagus and stomach. An increased risk of stomach cancer is observed among people who consume a lot of salt, mainly through foods that are preserved by salting. Despite the fact that at present our knowledge is not sufficient to accurately indicate all the components of nutrition that contribute to the development of cancer or, conversely, reduce the risk of its development, there is no doubt that a change in diet towards increasing the consumption of vegetables, herbs and fruits and reducing the consumption of fat and foods rich in fat will lead to a reduction in the incidence of malignant tumors. Food labeling for essential ingredients plays an important role in implementing these recommendations.

An essential component of cancer prevention through dietary modification is improving food storage methods, with limited use of salt for food preservation.

PROFESSIONAL CARCINOGENS. Available epidemiological data, as well as an assessment of the carcinogenic risk to humans of occupational factors conducted by the International Agency for Research on Cancer have shown that 29 substances used in industry or industrial processes increase the risk of cancer in humans. Some of them are widespread both in highly industrialized countries and in countries with a relatively low level of industrial development. In addition, experimental and epidemiological studies have shown that about 100 substances that people come into contact with in production conditions are also suspected of being carcinogenic.

The proportion of cancer cases attributable to occupational exposure is difficult to estimate, but estimates range from 1 to 4% all malignant neoplasms. However, there is considerable variability in the proportion of malignancies associated with occupational exposure, which may be significant in industrialized regions. For example, the incidence of bladder and lung cancer can be very high in regions with developed industry and poor hygienic exposure controls.

Malignant neoplasms of occupational origin, especially when the cause is established, are more easily preventable with the help of appropriate technological measures than malignant neoplasms associated with household factors. Carcinogenic occupational factors are rarely presented in the form of one specific substance. More often we are dealing with complex mixtures, not all of whose components may be known.

To reduce the incidence of occupational cancer, it is recommended

1. Eliminate known occupational carcinogens from production or reduce their level, at least to the standards adopted in the European Economic Community, with constant monitoring.

2.. Make public all known occupational carcinogens, including their appropriate labeling.

3. Determine the number of workers exposed to known occupational carcinogenic factors, and establish the prevalence of these factors.

4. Regulate internationally the transfer and use of carcinogenically hazardous industries and technologies.

5.Create conditions for economic incentives for the design and construction of “clean” enterprises and improvement of hygienic conditions in existing enterprises.

AIR POLLUTION. Epidemiological evidence suggests that high levels of urban air pollution and proximity to certain types of industrial plants, such as ferrous and non-ferrous metals, may be associated with an increased risk of lung cancer. Ambient air pollution may play a role in the development of other forms of malignant tumors.

The main carcinogenic air pollutants include polycyclic aromatic hydrocarbons (PAHs), asbestos and some metals. Benz(a)pyrene (BP) has been adopted as an indicator of PAH air pollution. The main sources of air pollution are enterprises of the metallurgical, coke-chemical, oil refining and aluminum industries, as well as thermal power plants and road transport. Epidemiological data indicate an increased risk of lung cancer due to ambient air pollution. A study conducted in 26 industrial cities of the Russian Federation showed that the incidence of lung cancer among men correlates with indicators of air pollution. However, the same study showed that the correlation is better with indicators characterizing the levels of consumption of tobacco products in these cities.

Based on analytical epidemiological studies conducted in a number of foreign countries, it can be concluded that after taking into account smoking, the relative risk of lung cancer associated with air pollution does not exceed 1.5. The greatest increase in risk (1.6 and 2.0) was found in people living near metallurgical plants. An increased risk of lung cancer in women living near a smelter was associated with levels of arsenic air pollution. In all of these studies, smoking and occupational employment in the metallurgical industry were taken into account when calculating relative risk.

Based on calculations made in epidemiological studies carried out in Krakow, it can be said that 4.3% of lung cancer in men and 10.5% in women is caused by air pollution. The same study showed that 74.7% and 20.6% of lung cancer in men and 47.6% and

8.3% in women is caused by smoking and occupational exposure to carcinogens, respectively. Similar estimates were obtained in a number of other epidemiological studies conducted in other countries.

Levels of PAHs in atmospheric air significantly exceed the maximum permissible concentration (1 ng/m3). For example, a metallurgical plant and a coke plant emit more than 2 kg of BP per day, and oil refineries emit more than 3 kg. The concentrations of BP in the emissions of these industries are extremely high, both for the working area and for populated areas. The dispersion of emissions beyond the border of the sanitary protection zone creates an excess of the maximum permissible concentration for coke production by 5-100 times, and for oil refineries by 10 times. Exceeding the MPC extends up to a distance of 10 km from enterprises. In some areas of Moscow, the average daily concentration of BP exceeds 20ng/m3, and the one-time maximum concentration is 100 ng/m3. It has been shown that exposure to other carcinogenic factors, such as smoking, may be aggravated by air pollution.

The difficulty of interpreting epidemiological data on the relationship between air pollution and the risk of malignant tumors can be explained by the inaccuracy of data on the levels of carcinogens in the air, as well as methodological problems associated with the need to separately assess the impact of various factors (air pollution, smoking, occupation) on the risk.

Although there is some uncertainty about the impact of air pollution on the risk of malignancy, measures aimed at further reducing emissions of carcinogens are warranted, in accordance with WHO policies in this area.

It is necessary to conduct epidemiological studies in heavily contaminated areas of Russia using methods that allow a quantitative assessment of the risk of developing malignant tumors.

Measures to prevent malignant tumors associated with air pollution by occupational carcinogens should be aimed at reconstructing enterprises that are the main source of air pollution, taking into account technology to reduce emissions, as well as control of vehicle emissions. In some cases, it will be necessary to raise the question of replacing outdated equipment, which has not met modern hygienic requirements for a long time.

IONIZING RADIATION. Ionizing radiation is carcinogenic to humans and leads to the development of almost all forms of malignant tumors. Detailed data on the carcinogenicity of various types of radiation (a, gamma, neutrons) and the “dose-dependence” of its effect were obtained as a result of epidemiological studies of the population of Hiroshima and Nagasaki, groups of people exposed to irradiation for medical purposes and among mine workers exposed to radon and products of its decay. A “dose-dependent” curve of radiation carcinogenesis has been described for various types of radiation. In addition, it was found that the carcinogenicity of a- rays is significantly higher than that of gamma rays.

In Hiroshima and Nagasaki, the peak incidence of leukemia was reached seven to eight years after the bombing, but the increased risk of leukemia persisted for more than 40 years. The increase in the incidence of solid tumors occurred much later: the risk was higher for those exposed to radiation at an early age.

Relatively recently, evidence has been obtained of an increased risk of cancer in people exposed to ionizing radiation in utero. In addition, it has been shown that the risk of leukemia is increased in children of fathers working at nuclear power plants and exposed to low doses of radiation. Most likely, the latter effect is the result of the mutagenic effect of radiation on germ cells.

Despite the accumulated experience and the possibility of extrapolation based on mathematical models, it is quite difficult to reliably predict the incidence of tumors among the exposed population when the radiation situation was different from the already observed situations. For example, as a result of the Chernobyl accident, the population was and, apparently, continues to be exposed to long-term effects of low doses of radiation on the entire body, the sources of which are soil, water and food. While the victims of the atomic bombings in Hiroshima and Nagasaki received external α-irradiation with an exposure duration of several seconds. Miners in the mines were exposed for a long time to a-particles that entered the body through the respiratory tract. The above suggests that it is necessary to constantly monitor the health of the population who have received increased doses of radiation, including measures for the early detection of malignant tumors. In addition, primary prevention measures should be implemented aimed at eliminating the influence of other known chemical and physical carcinogens on these people, namely, smoking, occupational carcinogens, as well as the use of radiological diagnostic methods. In addition, it is necessary to create a diet for them that reduces the risk of malignant tumors. Such primary and secondary prevention measures can lead to significant reductions in cancer incidence and mortality in populations exposed to ionizing radiation.

A significant increase in the risk of lung cancer in non-smoking women was revealed depending on the levels of radon exposure in residential premises; it can be assumed that some cases of lung cancer can be prevented by reducing indoor radon exposure. These measures should primarily be aimed at the correct selection of areas for building houses, as well as the elimination of building materials that may be sources of radon.

And yet, a person receives the most significant doses of radiation as a result of diagnostic and therapeutic measures (excluding extreme situations). Therefore, limiting the use of radiological diagnostic methods only to medical indications, using the lowest possible doses, will also lead to a reduction in the incidence of malignant tumors.

OTHER RISK FACTORS. In the etiology of malignant skin tumors, ultraviolet radiation plays a dominant role. Therefore, avoiding excessive exposure to sunlight, especially for people with very fair skin, will reduce the incidence of various forms of malignant skin tumors, including melanoma. The production and use of chlorofluorocarbon aerosols should be limited and ultimately eliminated because they deplete the ozone layer of the atmosphere and consequently increase levels of ultraviolet radiation.

In order to limit the spread of infectious agents that contribute to the development of cervical cancer, as well as AIDS and other diseases etiologically associated with viral infection, sex education programs should be introduced, primarily in schools, and the availability of cheap and good quality condoms should be ensured. Proper testing and processing of donated blood can significantly limit the risk of cancer and other diseases associated with blood-borne viruses. Blood testing is necessary for at least hepatitis B and HIV viruses, and possibly HTLV-l.

Thus, there is now convincing scientific evidence on the risk factors for malignant tumors, on the basis of which more than half of all cases of this disease can ultimately be prevented. However, cancer prevention measures, namely smoking control, dietary modification, hygienic measures to remove carcinogenic substances from enterprises and the environment in general, reducing exposure to ionizing radiation, and controlling viral infections require significant efforts from the state and society as a whole.

AGENTS AND INDUSTRIAL RECOGNIZED CARCINOGENIC TO HUMANS IN IARC MONOGRAPHIES (GROUP 1)

Agent/industrial process	Primary source of professional exposure	The main organ in which the carcinogenic effect is registered
Aluminum production		Lung, bladder
4-aminobiphenyl	Dye production	Bladder
Arsenic and its compounds	Production and use of arsenic-containing insecticides; mining; copper smelting	Leather; lung; liver
	Extraction;	production and use of insulating materials; textile industry; construction, repair of ships; cladding, covering
Lung; mesothelioma of the pleura and peritoneum		Bladder
	Auramine, production
Rubber industry; shoe industry;	Dye production	Bladder
oil refining	Benzidine
Bis(chloroethyl) ether and chloromethyl ether (technical)		Bladder
Mineral oils (raw and pre-processed)	Metalworking, jute processing
Mustard gas (mustard gas)	Benzidine
2-naphthalamine	Dye production	Bladder
Nickel and its compounds	Nickel purification	Nose; lung
	Mining industry
Rubber industry		Leukemia;
bladder	Shale oils
	Shale oil production
	Chimney sweeps	Production and use
Lung; pleural mesothelioma	Vinyl chloride	Production and polymerization
Angiosarcoma of the liver
Shoe production and repair	Chromium (hexavalent chromium compounds)
Production and use of pigments; chrome plating;
production of chromium alloys; stainless steel welding	Coal gasification	Coal tar pitch, tar/tar
Coal distillation; proprietary fuel; roofing; paving		Leather; larynx; lung; oral cavity; bladder
Coke production
Leather; lung; bud; bladder
Furniture making
Hematite mining (underground) with radon exposure

Iron and steel smelting

Production of isopropyl alcohol (technology using strong acids)

Malignant neoplasms, or cancerous tumors of various locations, are more relevant than ever today. Diseases are considered malignant if their growth is unlimited. A cancerous tumor can spread, grow, and metastasize.

Malignant neoplasms are successfully treated only in the early stages of development of the tumor process. Unfortunately, more than half of all cancer cases are detected only at stages 3 and 4, when there is no possibility of a complete cure. The cancer-causing factor is called carcinogenic. It is extremely important to prevent long-term exposure to carcinogenesis factors that increase the risk of developing cancer of any location.

Prevention of cancer (especially advanced cases of cancer) is determined, among other things, by timely diagnosis. Late detection of a cancerous tumor is often due to the absence of clear signs of suffering, or the patient’s ignorance of the early symptoms of the tumor process.

It is important to understand that cancer prevention is possible and feasible. It is much more effective than even timely detection of a cancerous tumor.

Malignant neoplasms most often reported in men- cancer of the lung, prostate, stomach, rectum, skin, pancreas.

Risk factors for cancer development are relevant at any age, despite the fact that malignant neoplasms are undoubtedly age-dependent human conditions.

Prevention of cancer should be carried out from a young age. It has been proven that the risk of developing cancer directly depends on a person’s lifestyle, diet, bad habits and the external environment around him.

We list the most important areas in which cancer prevention will be most effective.

1. Cancer Risk Factors Smoking tobacco

, which includes passive inhalation of components of tobacco smoke, reliably causes cancer of the lungs, stomach, throat, as well as malignant neoplasms of any localization, since tobacco components have a general carcinogenic effect on the body. Lung cancer is classified into central and peripheral. Early diagnosis of the latter is difficult.

Prevention of cancer development in heavy smokers consists of immediate cessation of smoking and exposure of the respiratory tract to other carcinogens (occupational pollution), preventive annual X-ray examination, including computed tomography (more often if necessary). When smoking cigarettes, the smoke that causes lung cancer also has a carcinogenic effect on the mucous membranes of the mouth (cancer of the tongue, tonsils), throat and larynx, and thyroid gland. Risk of developing cancer depends on age smoking

2. and number of cigarettes smoked (daily). Prevention of lung cancer involves avoiding inhalation of tobacco smoke (passive smoking) and using tobacco in any form. The risk of cancer increases with poor nutrition

3. , frequent consumption of foods that have carcinogenic properties. These hazardous food substances include smoked products (especially hot ones), fatty fried foods, especially those that are subjected to heat treatment for a long time without changing the oil, and deep-fried foods. The risk of developing cancer increases with, devoid of plant fibers and fiber, which slow down the advancement and peristalsis of the intestinal wall. Products containing many preservatives and chemical stabilizers (long-lasting ready-made meals), taste enhancers, are also not healthy and, if consumed regularly, can cause cancer and malignant neoplasms of the stomach and intestines.

Cancer-causing effects on the mucous membrane of the digestive tract are spicy dishes with lots of spices, hot foods and drinks consumed for a long time. These factors irritate the epithelium of the oral cavity, esophagus, and pharynx, causing inflammatory changes that contribute to degeneration into cancer.

Eating certain foods is effective in preventing cancer. So, the risk of cancer will be much lower if you eat garlic, grapes, dried fruits, turmeric, strawberries, corn, unrefined cereals, beans, green tea, kapust, pumpkin, citrus fruits, soy, a lot of vegetables, berries and fresh fruits.

4. Excessive radiation or sun exposure have an extremely negative effect not only on the skin, but also on the entire body as a whole, increasing the risk of developing cancer of any localization. Radiation burns can cause skin cancer and stimulate the degeneration of moles and birthmarks. Sunburn is especially dangerous for those with fair skin.

5. Chronic inflammatory diseases of the female genital area(uterus and appendages, cervical erosion), disturbances in hormonal regulation, infection with certain viruses, abortion, shortening of lactation time (breastfeeding) or complete refusal of breastfeeding - this is an incomplete list of risk factors for cancer of the female reproductive system and mammary glands.

Prevention of cancer development in women - timely treatment of inflammatory diseases, refusal of abortion, promotion of natural breastfeeding, vaccination, annual preventive gynecological examinations.

6. Infection of the stomach with a bacterium that causes chronic inflammation of the mucous membrane with its morphological restructuring ( Helicobacter pylori) is the main factor causing stomach cancer. Infection with this pathogen, in the absence of treatment, leads to ulceration and degeneration into stomach cancer. According to statistics, more than half of all people are infected with Helicobacter pylori.

Prevention of oncological diseases of the digestive system (stomach) consists of timely recognition of Helicobacter pylori, their eradication (destruction) and timely treatment of peptic ulcer, atrophic gastritis. Prevention of the development of intestinal (colon, rectal) cancer consists of consuming foods that have a protective effect on the mucous membranes, preventing constipation, and promoting the elimination of harmful and toxic substances.

7. Obesity- a risk factor for cancer and many human malignancies. With obesity, inflammation develops in adipose tissue and the release of pro-inflammatory factors that promote tumorigenesis. The risk of cancer in obesity has been proven in cancer of the breast and pancreas, liver, colon and other organs. In addition, malignant neoplasms are more aggressive in patients with obese, are less responsive to treatment.

8. Drinking alcohol significantly increases the risk of developing cancer. The effect of ethanol on the pancreas and liver is especially harmful, since cirrhosis of the liver that develops with chronic alcohol exposure can transform into cancer (cirrhosis-cancer). Reducing the dose of alcohol consumed, especially strong drinks and beer, slows down the course of liver fibrosis and the likelihood of the transition of chronic steatohepatitis to cirrhosis.

9. Exposure to ionizing radiation, radiation, magnetic fields, extreme temperatures(especially high temperatures, prolonged overheating) are the most important proven risk factors for cancer and all malignant neoplasms, as they trigger the process of uncontrolled cell growth. These physical impacts cause various mutations in somatic cells, and the risk of cancer increases many times over.

10. Cancer can develop as a result ecological troubles of the environment surrounding a person. The release of man-made carcinogens, industrial products and oil components leads to mutagenesis. The risk of cancer of any location, especially in conditions of hereditary predisposition, in large industrial centers and cities polluted by industrial waste and exhaust is several times higher than, for example, in rural areas.

11. Occupational hazards, working with petroleum products, dyes, coal tar, and inhaled carcinogens increases the risk of developing skin cancer (squamous cell carcinoma) and lungs.

12. Hundreds of cellular mutations occur in the human body every day. Damaged defective cells, potentially capable of forming malignant neoplasms, are immediately identified and destroyed by the immune system. Decreased immunity(congenital or acquired during life) - increase the risk of developing cancer. A cancerous tumor, during its development, also has an immunosuppressive effect (suppresses the immune system).

The combination of several risk factors increases the risk of developing cancer several times. A person pays with cancer for an incorrect lifestyle. Knowing the risk factors for cancer, it is within the power of every sane person to protect themselves and their loved ones from most malignant diseases.

Cancer prevention is a topic that interests most adults. Because almost every person in the family had cases of cancer. At the same time, you can see enough of the torment cancer causes and the severe side effects that arise from chemotherapy and radiation. In the CIS countries, an additional factor is the lack of normal pain relief under the pretext of combating the spread of drugs. For many reasons, cancer is a disease that scares us more than any other disease.

Cancer prevention - does not protect 100%, but still reduces the risk of cancer

Significant funds are allocated to the fight against cancer around the world. However, medical advances are modest at best. As for most types of cancer, humanity has not yet been able to curb them. Half of patients diagnosed with cancer die from them. Pay attention to cancer prevention as part of a set of measures to transition to a healthy lifestyle. Risk factors for cancer are known. Prevention is to avoid them. To do this, you need to instill healthy habits that reduce your risk.

Information about the prevention of various types of cancer is constantly updated. Yesterday the doctors recommended one thing, today another, and tomorrow something third will appear. For example, studies have shown that if beta-carotene is taken without other antioxidants, it not only does not protect against lung cancer, but rather increases the risk. In 2017, a large-scale study will be completed in the United States, from which accurate and definitive information is expected whether taking vitamin D capsules protects against cancer or not.

However, today you can follow several recommendations that are definitely effective in reducing the risk of cancer.

Do not smoke, chew or snuff tobacco	Smoking increases the risk of cancer by 10 times, especially lung cancer. Chewing tobacco causes cancer of the esophagus and pancreas.
Avoid exposure to secondhand smoke	Make every effort to breathe clean air, free from tobacco smoke. Passive smoking increases the risk of lung cancer by 24% and also accelerates the development of cardiovascular diseases.
Eat natural healthy fats. Avoid margarine and other trans fats	Learn more about what trans fats are and how they increase the risk of heart disease and cancer. Do not eat margarine, potato chips, or factory-made baked goods. It is advisable not to consume any processed foods. Eat fatty sea fish at least 1-2 times a week or take an Omega-3 fatty acid supplement.
Drink alcohol in moderation or stay sober	People who drink alcohol to excess have an increased risk of cancer of the intestines, lungs, kidneys and liver. Women who drink alcohol to excess have an increased risk of breast cancer.
Exercise and try to maintain normal body weight	Obesity carries almost as high a risk of cancer as smoking. Excess weight increases the risk of breast cancer in women, prostate cancer in men, as well as bowel, kidney and lung cancer. At the same time, regular physical activity has been proven to reduce the risk of breast and colorectal cancer.
Protect your skin from ultraviolet radiation	Stay out of the sun between 10 a.m. and 4 p.m. Don't sunbathe on the beach, relax in the shade. Wear a hat and sunglasses. Don't rely too much on sunscreen. Renew the cream layer on exposed skin areas more often.
Get vaccinated against viral infections	Hepatitis B can cause liver cancer, and human papillomavirus can cause cervical cancer. There are vaccines for both of these viruses. Vaccinations are recommended for men and women who practice promiscuity, injection drug users, and medical workers.
Get regular medical checkups	There are many types of cancer for which the earlier the tumor is detected, the greater the chance that treatment will be successful. In particular, these are cancers of the skin, intestines, prostate, cervix and breast. Discuss with your doctor how often you need preventive screenings.

Necessary theoretical information

To understand cancer prevention methods, it is useful to know something about the structure of cells. Your body is made up of many trillions of cells. Every cell has a nucleus. The nucleus contains the key to life—a long, twisted molecule of deoxyribonucleic acid known as DNA. Simply put, DNA contains the instructions (genes) that a cell needs to synthesize proteins and also make a copy of itself. If some abnormal changes occur in the DNA molecule, it is called a mutation.

Typically, cells in which a mutation has occurred recognize that they are damaged and die. This process is called apoptosis. And if suddenly apoptosis does not work, then the immune system tracks down the cancer cells and destroys them. But sometimes mutated cells begin to divide uncontrollably. From these, groups are formed that we call tumors.

Benign and malignant tumors

There are two types of tumors - benign and malignant. If the tumor is benign, then perhaps the cells in it are normal and not mutated. Benign tumors are usually not life-threatening. Cells from them do not spread to other parts of the body. Such tumors are removed surgically or suppressed with medications.

Malignant tumors are true cancerous tumors. Their mutated cells divide rapidly and randomly. They affect neighboring tissues and organs. The main threat is that cancer cells are released into the bloodstream and lymphatic system and migrate to other parts of the body. There they form new tumors - metastases.

Mutations usually occur when DNA molecules come into contact with free radicals, which are active destructive atoms. Free radicals enter the body from various sources. Some of them enter the body through chemical poisons, such as cigarette smoke or fertilizers. Others are made from unhealthy or low-quality food, such as smoked meats. Even exposing the skin to sunlight produces free radicals. Also, a lot of them are formed inside the body during metabolism. External factors that increase the risk of cancer are called carcinogens.

You don't have to completely avoid sunlight when trying to protect yourself from skin cancer. Just be reasonable. Do not sunbathe on the beach, but relax in the shade. Avoid being in the sun during the hottest hours - from 11.00 to 16.00.

Fortunately, nature has created a mechanism to counteract free radicals. They are neutralized by special molecules called antioxidants. It is our powerful weapon for preventing cancer and degenerative diseases.

How to reduce the risk of cancer:

Reduce the formation of free radicals in the body.
Avoid free radicals from the environment and food.
Take antioxidants and substances that strengthen the immune system.

Now let's discuss specific methods of preventing various types of cancer.

Risk factors for cancer

Cancer risk factors are divided into two large groups - hereditary and acquired. There is practically nothing we can do about hereditary risk factors. They are passed on with genes from generation to generation. However, they cause only 15% of cancer cases. The remaining 85% of cancers are caused by unhealthy diet, sedentary lifestyle, smoking and exposure to toxins.

Epidemiologists are doctors and scientists who study the prevalence of certain diseases and their risk factors. To estimate the likelihood of a particular person getting sick, they use the concept of relative risk. Let's say you have a certain circumstance or feature. Relative risk (RR) is a number that shows how much more likely a particular trait is to cause a disease compared to people who do not have that trait. For example, if Ivanov has a relative risk of 1.5, it means that his probability of developing the disease is 50% greater than for Petrov, whose relative risk is 1. A relative risk of 2 means that the probability of developing the disease is 2 times (100%) higher, etc.

Smokers have a 10-fold increased relative risk of cancer compared to non-smokers. In other words, they are 900% more likely to get lung or other cancer.

Relative risk is a statistical measure that is used to compare large groups of people. However, it is impossible to accurately predict the risk for an individual. Sometimes lung cancer occurs in people who have never smoked or inhaled anything particularly harmful. At the same time, some smokers never develop this disease and live to a ripe old age. Of every 10 lung cancer patients, one is not a smoker and has not been exposed to secondhand smoke.

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Genetic factors

Studies have been done on identical twins, who have 100% identical DNA. The results confirmed that most cancer cases are not associated with genetic defects. Nutrition and lifestyle are much more important. This turned out to be true even for those cancers that often occur in several generations of the same family.

Researchers have discovered about 30 genetic abnormalities that increase the risk of certain types of cancer. Some of them are rare. Hereditary cancers mostly develop in childhood. Conclusion: If you are no longer a child, then focus on eliminating the acquired risk factors, which are described below.

Is genetic testing worth it?

Many people know that breast cancer in women occurs due to genetic reasons. Indeed, there are two genes whose function is to prevent breast cancer. If a woman inherits these mutated genes, she has a slightly over 50% chance of developing breast cancer before the age of 70. Women with a bad family history also have an increased risk of ovarian cancer. However, genetic causes are responsible for only 10% of breast cancer cases.

If you have a history of cancer in your family, talk to your doctor about the possibility of genetic testing. However, you need to understand the benefits and risks of this. Genetic testing for cancer risk is very expensive, and its benefits are questionable.

When it comes to breast cancer, genetic testing is not recommended for all women. Only one in 850 women carries the mutation. Testing is still expensive. From a public health perspective, it is not justified. Moreover, even if testing shows that your genes are mutated, you still have about a 50% chance of getting breast cancer.

To protect yourself from hepatitis and human papilloma viruses, do not inject drugs and be selective in your sexual relations. Hepatitis vaccination is needed for medical and social workers who have a lot of contact with patients.

Let's say you decide to undergo genetic testing and find out that you have an increased risk of certain types of cancer. This means that you need to be examined more often, lead a healthy lifestyle and diligently protect yourself from exposure to environmental risk factors. The same advice can be given to all people without undergoing expensive testing.

Age and family history

The older you get, the higher your risk of cancer. Unfortunately, nothing can be done about this. As we age, our cells become less able to eliminate DNA mutations. As a result, more mutated cells continue to function in the body. More than 60% of new cancer cases and more than 70% of deaths due to cancer occur in people over 65 years of age.

Many types of cancer tend to run in families. For example, if a woman has two first-degree relatives (mother, aunt or sister) who have breast cancer, her own risk of breast cancer is increased by 2-5 times. The same applies to prostate cancer in men. However, few types of cancer are “familial”.

Other past diseases

Sometimes some past diseases increase the risk of others. There are diseases that have been proven to increase the risk of cancer. These are alcoholism, chronic hepatitis, diabetes mellitus, genital herpes, HIV infection, inflammatory bowel diseases, gastric and duodenal ulcers. If you are sick or have been sick with any of the above, then you need to make more efforts to prevent cancer.

Radiation and chemotherapy used to treat cancer increase the risk of developing other cancers in the future. It is possible that hormone replacement therapy and birth control pills increase the risk of breast cancer. But this has not been proven.

Unfavorable environment

Exposure to tobacco smoke is a major risk factor for cancer. Besides this, there are also environmental factors. These are pesticides, herbicides, heavy metals (mercury, lead, cadmium and others), asbestos, solvents, being near power lines (not proven!). The risk depends on the concentration, duration and intensity of contact with toxic substances. It has been demonstrated that the risk of cancer is significantly increased in workers who professionally handle heavy metals and other poisons in high concentrations.

A healthy lifestyle plays a leading role in the prevention of cancer. What do we have to do:

Do not smoke or be exposed to secondhand smoke.
Exercise regularly.
Drink alcohol in moderation or be a total teetotaler.

Smoking

Smoking is the leading risk factor for preventable cancer. Smoking causes about 90% of all lung cancer cases. The risk of dying from lung cancer is 20 times higher for men who smoke, and 12 times higher for women who smoke, compared to those who do not smoke. Smoking also increases the risk of almost all other types of cancer. It is responsible for at least 30% of all deaths from cancer. Smoking is also the main cause of heart attacks, strokes, chronic bronchitis and emphysema.

Passive smoking—when someone smokes and you breathe it in—is an important risk factor for cancer, especially lung and breast cancer. It may increase the risk of cardiovascular disease even more than active smoking. It is assumed that the body of passive smokers is not used to dealing with free radicals, and therefore they cause especially severe damage. If a woman does not smoke but lives with a smoker, her risk of developing lung cancer is increased by 24%.

Sedentary lifestyle and alcohol

A low level of physical activity and a sedentary lifestyle increase the risk of cancer. Several large-scale studies have convincingly confirmed this fact. Regular physical activity almost halves the risk of cancer. It could be physical education or physical labor - it doesn’t matter. The more active a person is physically, the lower his risk of becoming closely acquainted with oncology. This is especially true for colon and breast cancer. If you have any risk factors for cancer - poor diet, excess weight, smoking - these can be partially balanced by regular exercise.

In the human body, alcohol turns into acetaldehyde. It is a toxic substance that acts as a free radical and causes DNA mutations in cells. Alcohol stimulates the development of many types of cancer. And the more a person drinks, the higher his risk. Moderate alcohol consumption carries little or no risk of cancer. This is one glass of wine, beer or one serving of spirits per day. However, if you drink in excess, the risk of cancer of the liver, intestines, pharynx, and breasts in women increases.

Psychological factors

The level of stress, emotional background, positive/negative thinking and beliefs - all this plays a role in the development of many diseases, including cancer. A person's personality type largely determines what diseases he is prone to. Type A personality are people who are nervous, easily excitable, scandalous, pushy, and love to compete. They are difficult to get along with. Such people are more likely to have heart attacks and strokes, which are preceded by hypertension.

Cancer mainly affects people with personality type C. They are used to suppressing their emotions, especially anger. Such people want to avoid conflicts at all costs, show excessive patience, try to please others, and often feel helpless. In stressful situations, they try to suppress their true emotions, not show them, but look sweet and pleasant. It is assumed that this behavior makes a significant contribution to the development of cancer. Because stress suppresses the immune system, and suppressing emotions increases the effect several times.

All this has not been officially proven by psychological science. But based on personal observations, you will agree that in practice this is the case. How a person copes with stress is much more important than the reason that caused the nervous condition. Two people can experience the same stressful event, but they react to it differently. As a result, one will develop cancer, while the other will not.

Learn stress management techniques. It will be useful in any case. Learn to cope with stress through physical activity, relaxation techniques, and, if necessary, professional help from a psychologist. This will support your immune system, which can effectively track and promptly destroy colonies of cancer cells, preventing them from taking root. On the other hand, poor stress management techniques have a devastating effect. The black list includes suppression of emotions, alcohol abuse, overeating, and anti-anxiety pills.

Nutrition

It is believed that poor nutrition is the main cause of cancer. Smoking is in second place. Quitting smoking is usually easier for people than developing healthy eating habits. If a person eats “junk food,” then his body does not have enough vitamins, minerals and other nutrients to keep its cells and tissues healthy. The functioning of the immune system deteriorates, and it may be powerless against cancer.

Poor nutrition stimulates weight gain. Since the late 2000s, scientists have believed that obesity carries nearly as high a risk of cancer as smoking. Women who are overweight later in life after menopause have a 50% increased risk of breast cancer. For obese men, the risk of bowel cancer is increased by 40%. Gallbladder cancer occurs 5 times more often in obese people than in thin people. There is also an increased risk of cancer of the kidneys, pancreas, liver and esophagus.

It is believed that significant consumption of red meat increases the risk of cancer. However, the site recommends it for combating hypertension, cardiovascular diseases, joint problems, and most importantly, for losing weight.

Foods that increase your risk of cancer:

Sugar and products that contain it;
White flour, any refined carbohydrates;
Trans fats - margarine, processed foods, potato chips;
Excessive calorie intake;
Excessive alcohol consumption.

Foods that reduce cancer risk:

Fatty sea fish (herring, red fish, mackerel, cod liver, etc.);
Legumes - beans, peas, lentils and others;
Any greens, zucchini, cucumbers, cabbage;
Nuts.

Eating fruit, as well as beets and carrots, is believed to reduce the risk of cancer. However, it is better to stick to a diet that excludes these products. Fruits, beets and carrots provoke obesity, increase blood pressure, and do more harm than good. Don't get carried away with fruit. Instead, eat more greens and green vegetables.

Vitamin D and cancer risk

The connection between vitamin D deficiency and increased cancer risk was first established in 1980 by the Garland brothers at the University of California, San Diego. They found that colon cancer was 3 times more common in New York than in New Mexico. What is the reason for this? The Garland brothers suggested that the lack of sunlight in New York might be the reason, and published the first article on this topic.

Recent studies confirm that vitamin D deficiency in the body increases the risk of premature death and cancer almost as much as smoking. Nowadays, people are terrified of sunlight and avoid it to prevent skin cancer. However, as a result, for every one person avoided skin cancer, 55 women die from breast cancer. Another 55-60 men die from prostate cancer. This estimate is controversial in medical journals, but experts agree that a lack of vitamin D dramatically increases the risk of breast and colon cancers.

Food sources of vitamin D cannot completely replace sunlight. If you live in a cloudy climate, take vitamin D3 supplements.

A 4-year study was conducted in which 1179 post-menopausal women participated. Some of them were given 1100 IU of vitamin D per day, and others were given a placebo. It turned out that taking vitamin D reduced the incidence of all types of cancer by as much as 60%. Research the symptoms of vitamin D deficiency and consider taking it in capsule form. This is especially true for people living in regions where the weather is often cloudy.

Regular medical examinations

One of the measures to prevent cancer is regular examinations. This is especially important for people who have risk factors such as a family history of cancer or who work with toxic substances. During the examination, doctors will look for colonies of cancer cells, trying to identify cancer at an early stage, when the chances of successful treatment are highest.

People aged 20 to 40 years old are recommended to see a doctor every 3 years, and over 40 years old - every year. The doctor may refer you for special examinations - thyroid gland, oral cavity, skin, lymph nodes, male testicles, female ovaries, etc. Regular examinations are a powerful prevention for many types of cancer - breast, intestinal, cervical, prostate, testicular, oral cavities, skin. The listed types of cancer occur in half of all cancer cases. The earlier they can be detected, the greater the chance that treatment will be successful.

Watch your skin, pay attention to its unusual changes. Women are also encouraged to check their breasts themselves for lumps. This must be done monthly. Starting at age 40, you should have a mammogram every 2 years and visit a mammologist once a year. At the age of 20-39 years, it is advisable to consult a mammologist once every 3 years.

Prevention of colon and rectal cancer

Starting at age 50, men and women are recommended to undergo regular screening using one of the options listed below:

Fecal occult blood test every year, as well as flexible sigmoidoscopy every 5 years.
Colonoscopy every 10 years.
Barium enema with double contrast - every 5 or 10 years.

Simultaneously with sigmoidoscopy, colonoscopy or barium enema, you must also undergo a digital rectal examination. If you have a family history of bowel cancer, you need to be examined more often and more thoroughly. Discuss this with your doctor.

Prostate cancer

Men over age 50 who have a life expectancy of 10 years or more should have a prostate-specific antigen blood test and digital rectal examination annually. The same goes for men under 50 who have special risk factors. People at higher risk include black men and if you have two or more cases of prostate cancer in your family. In this case, you need to start getting examined annually from the age of 45 years.

Women's cancers

All women aged 18 years and older who are sexually active are recommended to have an annual Pap smear and pelvic examination. If three times in a row the Pap test shows that everything is fine, then it can be tested less frequently. If there are cases of uterine cancer in the family, then with the onset of menopause, samples of endometrial tissue should be checked.

conclusions

Brief abstracts:

Cancer develops as a result of DNA mutations in the nuclei of cells.
Don't eat junk food that contains free radicals, but eat natural foods.
Avoid exposure to environmental toxins.
It is advisable to take antioxidants and sometimes also immune system stimulants.
Smokers have a 10-fold increased risk of cancer!
Obesity increases the risk of cancer almost as much as smoking.
Cancer most often occurs in people with a Type C personality who suppress their emotions, especially anger.
The earlier cancer is detected, the greater the chance that it can be successfully treated.
In middle age and old age, undergo regular medical examinations.

The main ways to prevent cancer are to quit smoking, avoid exposure to second-hand smoke, eat natural foods, exercise regularly, and do not abuse alcohol.

Dangerous failures during cell division occur every second, but in a healthy body, altered cells face immediate death.

Cancer occurs when mutated cells are not destroyed by the immune system, but continue to divide, but according to their own pathological program.

The likelihood of such an outcome increases sharply in the presence of risk factors that favor the development of the disease.

Poor environmental situation

A polluted environment contributes to the increase in the number of cancer diseases. Industrial emissions into the atmosphere saturate the air with many toxic substances that can serve as a trigger for the development of cancer. The situation with the state of water and soils is no better. Residents of large cities are at risk, especially those who live near factories, thermal power plants and major highways.

Smoking

This bad habit is closely linked to the development of cancer. Nicotine and numerous substances contained in tobacco smoke poison the body and provoke the occurrence of malignant tumors of the oral cavity, and many other organs.

The risk is higher the earlier a person became addicted to smoking and the more cigarettes he smokes per day. Smokers develop oral cancer 2-3 times more often than non-smokers and 10 times more often when smoking more than 1 pack daily. Regular passive smoking also increases the chances of encountering a terrible diagnosis - by as much as 30%.

Alcohol abuse

Casual drunkenness causes cirrhosis of the liver, and this can lead to... However, drinkers risk encountering not only a tumor of this location. Toxins formed in the body after the breakdown of ethyl alcohol provoke dangerous mutations that contribute to the development of tumors in the bladder and other organs.

Poor nutrition

An excess of heavy fatty foods, semi-finished products and smoked foods in the diet becomes the main provoking factor for the occurrence of 35% of oncological pathologies of the stomach, colon, etc. Particularly dangerous are those that are deeply fried with a black-brown crust, where many carcinogens, synthetic fats, and products with a large number of artificial food additives and preservatives accumulate.

Overweight

Obesity is a leading risk factor for 13 types of cancer, including breast cancer, and. Adipose tissue synthesizes female sex hormones - estrogens, whose excess in the body causes the formation of hormone-dependent tumors.

Fat deposits in the abdominal area cause changes in the composition of the intestinal microflora, which leads to chronic inflammatory processes in the digestive system. And from damage to the mucous membrane of the stomach and intestines - a short distance to.

Other dangerous changes in organs due to obesity include fatty liver, cholesterol stones in the gall bladder, and an increase in the size of the thyroid gland. All of these pathologies increase the risk of developing cancer.

Sedentary lifestyle

Insufficient physical activity significantly increases the risk of malignant lung tumors in men and breast cancer in women. Physical inactivity contributes to weight gain, metabolic and intestinal motility disorders, and weakened immunity, which provokes carcinogenesis.

Old age

The longer a person lives, the higher their chances of encountering cancer of all forms. Most often, malignant tumors are found in people over 60 years of age, so in old age it is important to regularly carry out early diagnosis.

Some chronic infections

About 15% of cancer cases are caused by carcinogenic infections: human papilloma viruses, hepatitis B and C, Epstein-Barr, as well as a type of pathogenic bacteria Helicobacter pylori.

Thus, the human papillomavirus increases the risk of cervical cancer. This infection is transmitted sexually.

Infection with hepatitis B and C viruses, if the disease becomes chronic, can first provoke cirrhosis, and then liver cancer. The hepatitis B virus is transmitted through unprotected sex, and the hepatitis C virus is transmitted through blood.

Epstein-Barr virus causes infectious mononucleosis, which can develop into brain lymphoma. The danger of encountering this formidable complication is real in the presence of diseases that sharply reduce immunity.

The spiral-shaped bacterium Helicobacter pylori, the causative agent of Helicobacter pylori, causes gastritis and other chronic diseases of the gastrointestinal tract. In turn, persistent damage to the mucous membranes of the stomach can lead to uncontrolled tissue growth and the development of cancer.

Ionizing and ultraviolet radiation

Radiation is an extremely powerful mutagen that can damage cells at the molecular level. Hence the conclusion: you should undergo X-ray examinations and other medical procedures associated with ionizing radiation only if there are serious indications.

Ultraviolet radiation also has carcinogenic properties. Fans of extreme tanning are more likely to develop various types of skin cancer compared to those who avoid tanning beds and limit exposure to the sun: Blondes and red-haired people with a tendency to freckles are most at risk.

Harmful production factors

Work in many industries involves long-term exposure to chemical carcinogens that can cause cancer. Workers at chemical and petrochemical enterprises, painters, fuel tankers, bitumen workers and representatives of a number of other professions are at risk.

From the point of view of carcinogenesis, the greatest danger from inorganic compounds is polycyclic and heterocyclic aromatic hydrocarbons, chemical dyes, nitroso compounds, epoxides, asbestos, arsenic, chromium compounds and a number of others. There are also many carcinogenic substances of organic origin - these include, in particular, soot, technical oils, paraffins, benzene, and aflatoxins.

Occupational prerequisites for the development of cancer may also include exposure to physical factors - ionizing and ultraviolet radiation, which were discussed earlier. In these cases, employees of X-ray rooms and physiotherapy rooms, electric welders, and metallurgists come under attack.

Typical occupational tumors include malignant neoplasms of the lungs, skin, and bladder. Less common are cancer of the esophagus, larynx, and liver sarcoma.

Unfavorable heredity

Having a family history of cancer increases your risk of developing cancer. Let's take an example with breast cancer: if this diagnosis was made to relatives on the father's side, then the risk of a tumor in his daughter increases by 2-3 times, and if the disease is on the maternal side - by 12 times.

Popular oncology clinics and centers

The British Clinic London Bridge Hospital considers the diagnosis and treatment of malignant tumors one of the priorities in its activities. The clinic’s specialists effectively treat cancer of any location and complexity. The staff consists of doctors with extensive experience and high qualifications.

The South Korean SEM Hospital has in its arsenal modern medical and diagnostic equipment for the treatment of malignant tumors of various locations, including a 16-slice PET-CT, CT with a multi-row arrangement of detectors, and equipment for radiofrequency ablation.