Biostatisticians from Yale University’s School of Public Health have developed a mathematical model to calculate the ratio of various factors in the development of 24 cancer types. Scientists talked more about this in an article in the journal Molecular Biology And Evolution.
To assess the contribution of each known factor, the researchers took into account both the influence of the environment and known genetic mutations. It turned out that external causes play an important role in the development of melanoma and bladder cancer, but prostate cancer and glioma are largely due to internal processes associated with age.
While this approach does not provide important new information, it does provide an opportunity to assess cancer risk in individual patients or groups of people, such as workplaces or areas where abnormally high cancer rates are observed.
“It can be useful in terms of giving people feedback that lets them know what’s causing their cancer. Maybe not everyone wants to know about it. But on a personal level, it can be helpful for people to associate the disease with the cause,” say the study’s authors.
In addition, the model could allow doctors to assess the risk of developing certain types of cancer in patients and make timely recommendations to them. This approach can also be used on a larger scale, taking into account all possible risks when developing cancer prevention strategies.
“Public health interventions to minimize exposure to avoidable risk factors can reduce the severity of the disease by preventing the accumulation of mutations that directly contribute to the development of cancer,” the researchers wrote.
“Scientists have long sought to assess the extent to which any person’s tumor develops as a result of preventable actions (for example, UV exposure, smoking, etc.) compared to aging or random mutations. Previously, other groups of scientists had already shown that it is possible to reliably predict how certain factors that cause certain mutations alter the genome in tissues. Combining this information with their method of measuring each mutation’s contribution to cancer, the researchers showed a certain percentage of blame should be placed on known and unknown factors in the occurrence of cancer,” the chief of oncology at SM-Clinic told Gazeta. Ru, Doctor of Medical Sciences, Professor Alexander Seryakov.
“In general, attempts to prevent the development of cancer remain current and new ways of prevention need to be sought, but there will probably not be special prospects and prerequisites for the development of this field in the near future. This is especially true for the most common diseases (as risk factors have been studied in some detail in these cases).
But with regard to rarer types of cancer, this remains extremely relevant, as these diseases are still difficult to detect and treat early, ”said Suna Isakova, an oncologist at the SberHealth medical online service, in an interview with socialbites.ca.
Seryakov points out that cancer is the second most common cause of death in Russia. About 4 million cancer patients are registered in the country.
The most well-studied factors that increase the risk of developing cancer, hereditary predisposition, infectious diseases that cause chronic inflammation, smoking, alcoholism, bad environment, radiation, ultraviolet radiation, reduced immunity (including as a result of chronic stress and depression), Seryakov, hypodynamics, overweight, with carcinogens He says he is in frequent contact. Nutrition also plays an important role.
“Every third case of cancer of the pancreas, intestine, stomach is associated with a systematic imbalance in the diet,” the doctor adds.
– Carcinogens include fried foods, smoked foods, large amounts of fast carbohydrates and trans fats, abundant protein foods of animal origin (more than 1/5 of the total volume), nitrates accumulated in vegetables and fruits grown on an industrial scale. , where nitro compounds are used for accelerated growth and development of plants.
About 10% of cancer cases are related to heredity. It plays a role especially in the development of breast and ovarian tumors in women, prostate cancer and intestinal cancer in men.
“The risk factors for common pathologies have been studied in some detail. Ultraviolet radiation, smoking are probably factors known to a large number of people. Also, external factors include hepatitis B virus (especially in combination with hepatitis D), highly oncogenic strains of the human papilloma virus (6.11, 16, 18, etc.) Quite rarely, infection with aflatoxin B1, from which liver cancer develops, ”says Isakova.
Women most often experience breast cancer, the main role in the development of which is played by hereditary factors (mutations in the BRCA1, BRCA2, CHEK2, NBS1 and other genes) and reproductive factors associated with prolonged exposure to estrogens in the mammary gland – early onset of menstruation, late menopause, then the first birth of the child.
“Other factors that increase the risk of developing breast cancer include alcohol use, overweight and obesity, and physical inactivity. These factors are considered the main factors in 21% of all breast cancer deaths in the world,” says Seryakov.
Lung cancer among men is the most common, at the same time it remains the first in Russia and in the world in terms of death among men and women.
In addition to smoking, which is considered the most common cause of lung cancer, genetic predisposition also plays a role, work in hazardous industries associated with radiation, dust, inhalation of chemicals, life in megacities and near large industrial enterprises, overweight, malnutrition, alcoholism, old age and stress.
“Among professions with a high risk of oncology, metallurgists lead with an indicator of 41.18%, and builders with an indicator of 11.76% of cases,” adds Seryakov.
– The most dangerous occupation is electric and gas welder. Representatives of this profession are most often diagnosed with tumors. Oncological diseases constitute 0.33% of all occupational diseases. Due to harmful and difficult working conditions, bronchi and lungs (64.71%), stomach and larynx (11.76%), kidneys (5.88%) are most affected by cancer.
Working with asbestos is also dangerous for the lungs, but a significant increase in the risk of developing lung cancer is only worth worrying about with prolonged contact – for example, those who work in processing plants, mines and processing plants.
“Oddly enough, office work is associated with an increased risk of developing cancer,” says Isakova. – The connection of a sedentary lifestyle with some oncological diseases – intestinal and ovarian cancer has been proven. It is also dangerous to work with pesticides, welding equipment, work related to ionizing radiation.”
The risks of developing cancer increase with age, and people between the ages of 51 and 73 are at greatest risk.
“Each age is characterized by the development of its own type of cancer, certain organs suffer with age,” explains Seryakov. – Statistics on the importance of cancer development by age show that in patients under 20 years of age (mean age 15 years), mortality is minimal and reaches 0.3%. According to 2020 world statistics, there are 18 million new cases and 9.6 million sick deaths among the elderly. These data are valid for today. The accumulation of mutations in genes with age is one of the main reasons that cancer will probably never be completely replaced. The problem of fighting cancer is closely intertwined with the problem of aging of the population.”
Isakova emphasizes that more attention should be paid to the diagnosis of cancer in adulthood. It is recommended to donate feces for occult blood every year from the age of 45 and to have a colonoscopy every 10 years. Men over 50 – take a blood test for PSA (prostate-specific antigen), women over 40-50 – undergo a mammogram every 1-2 years. Low-dose chest CT is recommended for smokers from 50 years of age.
From the age of 21, women should also do a PAP test (a smear from the cervix) every 3 years, and after 30 years – a PAP test with an HPV analysis every 5 years.
Regular clinical examination in Russia has proven to be an effective tool for early detection of the most common types of cancer.
“Mandatory clinical examination helps to diagnose cancer in the early stages almost eight times more often,” says Seryakov. – The list of examinations and studies within the framework of the medical examination depends on the age and gender of the citizen. So, for example, during a medical examination, women are examined by a gynecologist with a smear taken from the cervix for cytological examination, and from the age of 39 – by mammography. Performing a full cervical cancer screening can reduce the incidence of cervical cancer by 80% and the death rate from this disease by 72%. Mammography is an effective screening method for women over the age of 39. In 50 years, breast cancer mortality in women in countries where screening coverage exceeds 70% has decreased by 20-30% thanks to mammography.
Lung cancer can be detected by fluorography or, occasionally, by low-dose CT, which replaces it.
If a certain type of cancer is suspected, additional examinations are prescribed based on the results of the medical examination. The most informative of them is a biopsy of the affected tissues.
There is no way to guarantee 100% protection against cancer – even if all possible risk factors are excluded, random mutations may play a role. However, giving up bad habits can reduce the likelihood of developing cancer.
Seryakov notes that less obvious preventive measures include healthy sleep – for a healthy immune system and protection from cancer, you need to sleep 7-8 hours every night, and working the night shift is considered a possible carcinogen. In addition, natural coffee has a protective effect – about five cups a day reduces the risk of laryngeal cancer and malignant brain tumors. Walking in the fresh air is also beneficial because it reduces the risk of premature death, usually from all causes, including cancer.
Isakova also adds that vaccinating against hepatitis B and human papillomavirus, including men, will help protect yourself. Don’t forget sunscreen, too.