Cancer prevention

Cancer prevention is based on modern knowledge of the mechanisms of carcinogenesis. The experience of experimental and epidemiological studies indicates the existence of a direct connection between the impact of external agents, endogenous metabolites and the development of a tumor with a certain latent period under their influence. Prevention of the occurrence of malignant neoplasms consists of a set of measures for their primary and secondary prevention.

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Primary prevention of cancer

Such cancer prevention is aimed at eliminating or reducing the impact of carcinogenic factors (chemical, physical and biological) on the human body, reducing their impact on the cell, increasing the specific and non-specific resistance of the body. Primary cancer prevention is carried out using sanitary and hygienic measures, as well as by correcting biochemical, genetic, immunobiological and age-related disorders in humans, which allows reducing cancer incidence by more than 70%.

Individual protection of the body from malignant neoplasms should include the following measures:

• compliance with personal hygiene rules;
• therapeutic correction of impaired body functions;
• proper rational nutrition;
• giving up bad habits;
• optimization of reproductive system functions;
• maintaining a healthy active lifestyle;
• formation of high self-awareness of a person.

Oncohygienic prevention of cancer also involves eliminating carcinogenic impurities from inhaled air and water.

Air hygiene

The priority task is to combat smoking. Complete smoking cessation is the optimal means of individual lung cancer prevention.

Under the auspices of WHO, a Partnership Programme for European countries has been developed, aimed at uniting efforts to combat smoking and free smokers from tobacco addiction.

Along with quitting smoking, a responsible task is the fight for clean air, which is of particular importance for those working with occupational hazards, as well as for residents of industrial cities with an atmosphere polluted by industrial emissions.

Preventive measures include placing industrial enterprises outside the city limits, expanding green areas, creating closed production cycles, waste-free technologies, and installing catch filters at enterprises.

In residential areas, good ventilation of kitchens and living rooms is necessary, especially in houses with a high content of asbestos fibers, metal impurities and increased radioactive background.

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Physical activity

A person who has been sitting or sedentary for more than 5 hours a day has a high risk of developing congestion in all parts of the body and internal organs. This has a negative effect on the function of lymphocytes, which leads to hypoxia, hypoventilation and impaired drainage function of the lungs. When comparing groups of people with high and low physical activity, it was found that the incidence of malignant tumors was 60% lower in the first group. The value of physical exercise is obvious when it is carried out regularly.

Food hygiene

Among the factors contributing to the development of malignant neoplasms, the alimentary factor accounts for 35%. An important measure of individual cancer prevention is abstinence from excess nutrition and a reduction in the amount of fat in the diet. Reducing fat consumption to 20 - 25% leads to a decrease in cholesterol and estrogen levels and, consequently, the incidence of colon cancer, breast cancer, uterine cancer, pancreatic cancer and other organs. Men are recommended to limit themselves to 75 g, and women - 50 g of fat per day.

Cancer prevention also involves limiting fried foods, pickles, marinades, and smoked foods. It is necessary to exclude prolonged use of overheated fats, frying on open gas burners, or charring of products. This will reduce the content of carcinogens formed during the cooking process.

However, a low-fat diet alone does not solve the problem of cancer. To reduce the risk of the disease, the diet should be varied, it should include a sufficient amount of vegetables and fruits rich in vitamins, minerals, fiber and many unique biochemicals. They prevent the formation of carcinogens, slow down their activation and suppress carcinogenesis after exposure to a carcinogenic agent.

All fruits and vegetables are healthy, but the families of umbelliferous vegetables (carrots, parsley), cruciferous vegetables (cabbage, asparagus and other types of cabbage), vegetable oils, and soybeans are especially valuable.

Great importance is attached to vitamins A, C and group B. Vitamin A and carotenoids prevent the accumulation of carcinogens in the body and reduce their impact on cells. They prevent the development of cancer of the esophagus, stomach, lung, bladder, prostate and colon. Beta-carotene is effective in preventing spontaneous, chemical and radiation carcinogenesis, prevents the development of skin tumors induced by UV radiation. Vitamin C in large doses (up to 10 g) has antioxidant properties, inhibits the formation of nitrosamines from nitrites, stimulates immunity indicators, reduces the risk of cancer of the esophagus and stomach.

Prevention of colon cancer involves eating foods rich in coarse fiber and B vitamins. Poorly digestible plant fiber leads to dilution of carcinogens in large amounts of feces, accelerates the evacuation of contents from the intestine, changes the metabolism of bile acids, and reduces the pH of the environment.

Essential components for preventing malignant tumors are macro- and microelements. An important role belongs to selenium and calcium, the deficiency of which leads to an increase in the frequency of cancer and an increase in the processes of metastasis.

The European Cancer Programme contains a list of dietary recommendations.

1. The likelihood of developing cancer in different individuals is largely determined by genetics, but the current state of knowledge does not allow identification of people at high risk. Recommendations should be applicable to persons over two years of age.
2. There are specific dietary recommendations:
   • the calorie intake from burning fat should not exceed 30% of the total energy value of food. Including less than 10% should be provided by saturated fats, 6-8% - polyunsaturated fats, 2-4% - monounsaturated;
   • it is necessary to consume a variety of fresh vegetables and fruits several times a day;
   • It is necessary to balance physical activity and diet to maintain normal body weight;
   • You should limit your consumption of salt, food preserved with nitrites, nitrates and salt. The salt intake rate should not exceed 6 g per day;
   • limit consumption of alcoholic beverages.

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Secondary prevention of cancer

Secondary cancer prevention is a set of medical measures aimed at identifying patients with precancerous diseases with subsequent recovery and monitoring. The effectiveness of such prevention is undeniable, although it is far from the same for different localizations. Thanks to the detection of precancerous diseases at the level of examination rooms and their subsequent treatment, there has been a tendency to reduce the incidence of, for example, cervical cancer. The organization and implementation of measures for early cancer diagnostics is also considered secondary cancer prevention.

Preventive oncological examinations are performed on people over 30 years of age. Particular attention should be paid to elderly people. Examinations are performed by medical workers of the general medical network. Oncologists provide methodological guidance.

Preventive examinations must include mandatory external oncological examination, which includes examination and palpation of the skin, visible mucous membranes, peripheral lymph nodes, thyroid and mammary glands, cervix, testicles in men, digital examination of the rectum. Tumor damage to organs of the listed localizations accounts for more than 50% of the structure of oncological diseases.

A distinction is made between mass and individual inspections. Mass inspections are understood to mean the examination of significant contingents of people working at enterprises, institutions, collective farms and state farms, conducted according to a pre-planned plan.

Individual examinations are examinations to detect oncological diseases in people who have visited a polyclinic or are undergoing treatment in a hospital. In addition to patients who have come for an outpatient appointment, people working in the food industry, trade and preschool institutions, as well as disabled veterans of the Great Patriotic War, are periodically subject to individual examinations. It is mandatory upon employment and referral for sanatorium-resort treatment.

Depending on the objectives and scope of examinations, mass preventive examinations are divided into comprehensive and targeted.

Comprehensive examinations are considered to be examinations of the healthy population by a group of doctors of different specialties, conducted in order to identify various diseases, including malignant tumors. Such examinations are usually carried out at industrial enterprises, especially in hazardous industries: the nickel industry, uranium mines, aniline dye plants, etc. In agriculture, machine operators and milkmaids are subject to comprehensive examination.

Targeted examinations are those conducted to detect one or a group of similar diseases. The objective of these examinations is the early detection of malignant neoplasms and precancerous diseases. Targeted examinations are conducted by doctors or paramedical workers.

Targeted examinations performed by mid-level medical workers are called two-stage. They are used mainly in rural areas. In this case, a paramedic or midwife examines the entire healthy population, and those with suspected malignant tumors or precancerous diseases are referred to a doctor to clarify the diagnosis.

Mass preventive examinations must meet four basic requirements.

1. The examination methods used must have a sufficiently high resolution.
2. They must be technically simple and not require significant economic costs.
3. The frequency of examinations of various categories of the population should be determined by the likelihood of the occurrence of a malignant neoplasm.
4. Clear continuity must be ensured between the stages of screening and subsequent in-depth examination and treatment of patients.

The majority of the healthy population is usually subjected to preventive examination annually. People belonging to high-risk groups, as well as people working in hazardous industries, are examined more often, usually once every 6 months.

In recent years, there has been an intensive search for new forms of conducting preventive examinations. A wide network of fluorographic and examination rooms has been created. Preventive departments have been opened at city polyclinics. A questionnaire method for collecting information on harmful factors and the state of health of people is being introduced into practical activities. The analysis of the data obtained is carried out using special diagnostic tables or computer technology. Persons who have risk factors are subjected to an in-depth examination.

Early diagnosis of malignant tumors, which is currently the main condition for their successful treatment, should be carried out not as the patient seeks help from a doctor, but through appropriate screening programs, dispensary observation and in-depth systematic examinations of individuals included in the high-risk group for developing malignant neoplasms.

It should be noted that molecular biological studies can already be used as diagnostic tests in groups at increased risk of developing cancer. According to A. G. Tatosyan (2001), relatively inexpensive screening, noninvasive research programs based on the detection of altered fragments and combinations of oncogenes, for example, in sputum, can be developed on the basis of molecular biological methods. Individuals who are diagnosed with molecular precancer should avoid contact with carcinogens and systematically undergo in-depth medical examinations.

Tertiary cancer prevention

Prevention of cancer recurrence is considered as tertiary cancer prevention.

The effectiveness of prevention depends on the level of anti-cancer propaganda, which begins long before medical examinations and continues during them, using all channels and forms of mass and individual information.

Anti-cancer propaganda among the population sets the following goals:

• familiarizing the population with the first warning signs of cancer;
• belief in the need for regular medical examinations;
• developing the habit of consciously monitoring one’s health, teaching methods of self-examination (oral cavity, mammary glands, etc.);
• instilling confidence in the success of treatment if cancer is detected in a timely manner;
• Propaganda of a healthy lifestyle and sanitary and hygienic knowledge is the basis of such an event as primary cancer prevention.