Prevention is actions aimed at reducing the risk of developing a disease. That is, first you need to determine the risk factors.
The risk factors that can cause cancer include:
1) Smoking is one of the leading causes development of diseases such as acute myeloid leukemia, bladder cancer, esophageal cancer, kidney cancer, lung cancer, oropharyngeal cancer, pancreatic cancer, stomach cancer.
2) Certain types of infection are also capable of causing the development of cancer. Thus, the human papillomavirus is associated with the development of cancer of the cervix, penis, vulva, anus and oropharynx. Hepatitis B and C viruses are responsible for the development of hepatocellular cancer; Epstein-Barr virus is associated with Burkitt's lymphoma. The unfortunate bacterium Helicobacter pylori, which seems to provoke the development of gastric ulcer (there is quite a lot of controversy on this), can also be considered the cause of cancer.
We have already written that there is a specific prevention of these infections.
3) Ultraviolet radiation causes skin cancer, ionizing radiation can cause leukemia, thyroid cancer, breast cancer.
4) Immunosuppressants do not directly affect the development of the tumor, but reduce the overall immunity. (By the way, the opinion is quite popular among oncologists that cancer is, first of all, a mistake of the immune system.)
Presumptive influence on the development of cancer:
5) Alcohol , which is associated with the development of oral cancer, esophageal cancer, breast cancer, liver and colon cancer.
6) Obesity is associated with an increased risk of breast cancer in menopause , colorectal cancer, endometrial cancer, esophageal cancer, kidney cancer, pancreatic cancer, and probably pancreatic cancer.
7) Diabetes (and in particular insulin-like growth factor -1) may relate to cancer of the gallbladder, breast cancer in women (suddenly, because breast cancer can be in men), colon cancer, endometrial cancer, liver, lung, oral cavity, oropharynx, ovarian and pancreatic cancer .
8) Unhealthy diet. In general, there are quite a few opinions on this topic. There are various anti-cancer diets (and I, for example, cannot argue that they have no right to life), but there is an official list of potentially carcinogenic foods. These include, in particular, red meat. http://www.who.int/features/qa/cancer-red-meat/en/
9) Low physical activity is associated with the development of breast cancer, colorectal cancer intestines and endometrium.
Of course, the combination of diabetes, old age, obesity, smoking, an unhealthy diet and lack of exercise mutually potentiate cancer.
10) Environment also matters. Various chemicalsare related to different types of cancer: for example, air pollution, secondhand smoke and asbestosis are associated, for example, with the development of the risk of lung cancer. And drinking water with a lot of arsenic can provoke cancer of the skin, bladder and lungs.
What measures should be taken to reduce the risk of cancer?
1) Avoid the above risk factors.
2) Lead a healthy lifestyle (diet + physical activity).
3) Screening. In Russia, there is no system for centralized preventive examinations of the population, but they must be recommended without fail by the attending physician or family doctor. The list of studies to be done regularly is the same for all populations. In people with a high risk of developing cancer (the presence of certain hereditary syndromes, cancer in first-line relatives), the same studies should be carried out, but from an earlier age. The recommended age in this case is 5 years earlier than the earliest age at which a first-line relative was diagnosed with cancer (or from the recommended age at which screening began, whichever is earlier).
To me, alas, I could not find the latest information on screening programs in Russia, but I have university presentations.
4) Cancer chemoprevention. Here we are talking about conditions when a person has carcinoma in situ (a very small tumor, about stage 0) or there is a likelihood of reducing the disease after surgery. As a rule, this is a separate question.
Separately, we should talk about the genetic predisposition to the development of oncological diseases. It is known that, for example, there is a hereditary predisposition to the development of breast cancer due to mutations in the BRCA-1 and BRCA-2 genes. In this case, you need to consult a geneticist.
(However, a recent study came out according to which, even in the case of a hereditary predisposition to developing breast cancer, a healthy lifestyle reduces all risks.)
More information can be found on the website of the National Cancer Institute.
Oncological diseases can occur in genetically predisposed people, that is, if any of your relatives has any of the oncological diseases, then there is a possibility that his relatives may also have.
many viruses can cause cancer - cytomegalovirus, coxsackie, herpes, etc., that is, cancer can be prevented by preventing viral infections.
Physical (temperature, radiation) factors can cause tumors of the skin (sun), stomach ( hot food), chemical factors (benzpyrene, cigarettes and what they contain) can cause lung cancer, bowel cancer, etc.
Thus, avoiding all these factors can prevent cancer, and in general the topic big, that's me, I wrote briefly)
Prevention - avoiding risk factors.
Risk factors according to the version of the US National Cancer Institute.
Increasing the risk: tobacco, infections (viruses in the first place), rationing, immunosuppressive drugs.
May increase risk: Diet, alcohol, physical inactivity, obesity, diabetes, environmental risk factors (secondhand smoke, pesticides, additives).
Learn more can be found in the primary source at cancer.gov - about cancer - causes and prevention.
Stress may also play a significant role (alternatively, because it lowers immunity).
Unfortunately, there are few proven methods of prevention. Prevention of cervical cancer with proven efficacy - the Gardasil vaccine. Vaccination against hepatitis B will to some extent protect against liver cancer (as an outcome of chronic hepatitis B).
There are methods for early diagnosis (which makes it more likely to cure cancer), but this is not the subject of this question.
Also, many cancers have a positive correlation with age. Those. you can simply not live to see your cancer, but die from another cause (trauma, HIV, heart attack, stroke).