Tobacco contains more than 70 carcinogens. Smoking is not only implicated in the occurrence of lung cancer; it is also in that of the upper airways, the stomach, the urinary tract, etc. Prevention consists of quitting smoking pure and simple, insofar as even minimal consumption is still considered harmful.
Tobacco is the leading cause of cancer, both in France and worldwide. Similarly, smoking is the number one cause of preventable cancer.
In France, smoking is responsible for more than 35,000 cancer deaths each year, above all of the lung (about 90% of cases). Smoking is thus the leading cause of cancer death in subjects under 65 years of age. It is also involved in 50 to 70% of cancers of the upper aerodigestive tract (nose, mouth, neck, esophagus, etc.).
The increase in the level of risk is linked to the number of cigarettes smoked, and even more to the duration of exposure. This is how we evaluate consumption in pack-years (for example, a subject who has smoked 10 cigarettes a day for 30 years has a consumption of 1/2 pack × 30, i.e. 15 pack-years). Starting to smoke in adolescence carries an additional risk.
All forms of tobacco use are dangerous. This is true of course for cigarettes, but also for cigars, pipes, shisha and even chewing tobacco. Even passive smoking has been blamed for cancers.
It is estimated that with the avoidance of tobacco, we could avoid about a quarter of cancer-related deaths.
Prevention then involves quitting smoking altogether. The sooner this stop occurs, the greater the benefit; the longer the withdrawal, the better the chances of escaping cancer, with the risk almost disappearing after 10 to 15 years of withdrawal.
Alcohol consumption is responsible for 8% of cancers, making it the second most preventable cause of cancer death after tobacco.
Indeed, excessive alcohol consumption is implicated in the appearance of many cancers, in particular those of the esophagus and stomach, liver or colorectal cancers.
In addition, it reinforces the carcinogenic effect of other factors, such as tobacco.
The risk of cancer increases with the dose of alcohol consumed and exists even for consumption limited to one drink per day, for example for breast cancer. The risk becomes significant from ten glasses of alcohol per week, which corresponds to the recommendation of “maximum two glasses per day, and not every day”.
Total withdrawal must be required in true alcoholism (defined as dependence on everyday alcohol).
Lifestyle itself can be a risk factor. Factors related to nutrition and physical activity have indeed been identified as increasing the risk of cancer.
Food works on many levels:
Indeed, an increased body mass index (BMI) is associated with an increase in cancer of the breast, pancreas, kidney, colon or esophagus. Nearly 19,000 new cases of cancer in France were attributed to being overweight in 2015, i.e. 5.4% of all new cases of cancer.
For example, a high consumption of red meat and cold meats is directly associated with colorectal cancers, that of salt and salty foods is made responsible for stomach cancer. Finally, taking food supplements, including beta-carotene, has been implicated in certain cancers, such as lung cancer.
In contrast to these factors which can favor the appearance of cancers, others can on the contrary prove to be protective:
Breastfeeding, finally, is protective.
It is notable that the nutritional risk factors are globally the same as those implicated in vascular diseases. Geriatricians even believe that they are associated with an increase in Alzheimer's disease as well. Hence the really crucial importance of nutritional prevention.
UVA and UVB rays emitted by the sun are responsible for most skin cancers (about 2/3), and in particular melanomas. However, you could easily protect yourself from the bad effects of these rays by regularly applying sunscreen or by avoiding exposure to the sun during the hottest hours.
These cancers are constantly increasing. Skin melanoma is diagnosed in 15,000 people per year, with an increase of 3% per year over the period 2010-2018.
Contrary to popular belief, the danger does not only come from sunburn.
Two types of UV rays from the sun can reach the skin:
Both UVA and UVB rays increase the risk of skin cancer. It should be noted that some of these rays are not filtered by glass and you are therefore not necessarily protected behind glass (in a car for example).
To protect yourself, different means exist in addition to protection with a cream, because sunscreen only offers incomplete protection. It should therefore:
These tips are particularly valid for children and adolescents, who are the most fragile.
Some skins are more sensitive than others. This is the case for people with light skin, and blond or red hair. Indeed these clear phenotypes are more at risk of developing skin cancer.
Finally, people with a large number of moles or a family history of skin cancer are also at risk and should have their skin examined regularly by a dermatologist.
Many substances commonly found in the everyday environment are carcinogens. Their list is not only non-exhaustive, but is constantly being supplemented. The IARC counts several hundred of them. According to sources, 10 to 30% of cancers are due to these environmental factors.
Some exposures are clearly identified as carcinogenic. This is the case, for example:
Others are possibly carcinogenic such as very low frequency magnetic fields.
Some cancers develop from infections by viruses or bacteria, with the particularity in this case of transmissibility, including the sexual route. In reality, strictly speaking, it is not the cancers themselves that are transmissible, but the infectious agents in question.
4% of cancers are linked to infections:
Since these cancers are linked to transmissible infections, they may be preventable.
Thus, the use of condoms is effective in the fight against the transmission of sexually transmitted viruses, such as hepatitis B and HIV. The transmission of the human papillomavirus, on the other hand, can be done with sexual practices such as touching with dirty hands or unprotected fellatio. The use of a condom therefore only partially protects.
Vaccination can also be effective. This is the case for hepatitis B and, in part, for the human papillomavirus. The latter, in fact, only offers protection against uterine cancer in 70% to 90% of cases (because there are different types of papillomavirus). This incomplete protection therefore justifies regular screening for cancer of the cervix by a cervico-vaginal smear.
It should be noted that the vaccination against the papillomavirus concerns girls and boys.
Sources
