It is the primary risk factor for bladder cancer, yet it is little known and can be avoided.

Each year in France, nearly 20,000 people are affected by bladder cancer. A preventable risk factor is responsible for a large proportion of these cases.

Bladder cancer is one of the most common cancers in France. It affects men four times more than women and is most often diagnosed around the age of 70. Aside from age and gender, other risk factors have been identified, including one in particular: smoking.

Smoking is indeed the primary risk factor for bladder cancer. It accounts for about half of all cases, particularly among men, who are more likely to smoke than women. But as women smoke more and more, they are increasingly affected by bladder cancer. Today, among 18-75 year-olds, about 20% of women and 25% of men are daily smokers, according to Public Health France .

In addition to having a higher risk of lung and cardiovascular diseases, lung and breast cancer, smokers have a significantly higher risk of developing bladder cancer. "Smokers have a 5.5 times higher risk of developing bladder cancer than non-smokers," states the ARC Foundation for Cancer Research. The higher the consumption and duration of smoking, the higher the risk.

But how can we explain this link between tobacco and bladder cancer? "Tobacco smoke contains more than 4,000 chemicals," recalls the Léon Bérard Cancer Center . These substances, some of which are highly toxic, are inhaled, then pass into the bloodstream, are then filtered by the kidneys and end up in the bladder, where they are stored before being eliminated in the urine.

Aside from tobacco, bladder cancer can also be caused by occupational risk factors, which account for a significant proportion of cases. These include exposure to certain substances used in the tar, tire, textile, cosmetic, and pesticide industries. Certain medications and radiotherapy have also been linked to bladder cancer.

The best way to avoid developing bladder cancer—and other diseases associated with smoking—is to not smoke, or to quit. "A few years after quitting, their risk of developing bladder cancer drops by about half. If a person has stopped smoking for 25 years or more, their risk is the same as that of someone who has never smoked," says the Canadian Ministry of Health .