Why does quitting smoking still leave a risk of lung cancer?

People who have smoked for a long time still have a risk of developing lung cancer even after quitting.

Smoking damages most organ systems in the body. Cigarette smoke contains over 7,000 chemicals, many of which are toxic. At least 70 of these substances are carcinogenic to humans or animals.

In addition to increasing the risk of cardiovascular disease, emphysema, stroke, leukemia, asthma, pneumonia, and tuberculosis, smoking is the leading cause of cancer, especially deadly cancers.

According to the U.S. Centers for Disease Control and Prevention (CDC), 85% of lung cancer cases in the country are linked to smoking. Simply living with someone who smokes increases the risk of lung cancer or heart disease from secondhand smoke exposure by up to 30%. In total, smoking and exposure to secondhand smoke cause approximately 480,000 deaths each year in the U.S.

Smokers are 15-30 times more likely to develop or die from lung cancer than non-smokers. Even after quitting, the risk of lung cancer persists because the harmful effects of smoking can be long-lasting.

Carcinogens from cigarette smoke, when entering the body, can cause changes in lung cells. These changes can remain dormant for years before symptoms become apparent. Therefore, people who have quit smoking still have a higher risk than those who have never smoked. The level of risk depends on many factors, including the length of time and amount of cigarettes smoked.

A 2018 study published in the UK's National Journal of Cancer, from the Oxford Institute, noted that 40% of lung cancer cases were diagnosed in people who had quit smoking more than 15 years prior. The study involved nearly 4,000 original participants and over 5,000 of their children.

Researchers compared the risk of lung cancer in people who had smoked for many years with those who had never smoked. The results showed that the risk of lung cancer five years after quitting was still 12.12 times higher than in people who had never smoked, 7.81 times higher after 10-15 years, and 3.85 times higher after 25 years.

Therefore, health experts recommend quitting smoking as early as possible. According to a study published five years ago in the New England Journal of Medicine, quitting before age 40 reduces the risk of premature death from smoking-related diseases by 90%, and quitting before age 54 reduces this risk by two-thirds.

Even those who are currently smoking, if they quit after being diagnosed with cancer, are more likely to recover and respond to treatment better, reducing their risk of death from some types of cancer by up to 40%. The risk of developing other types of cancer continues to decrease the longer they remain smoke-free.

According to the American Cancer Society, within months of quitting smoking, the lungs begin to repair themselves. Cilia, tiny, hair-like structures in the lungs that help clean out debris, begin to regenerate, improving lung function and reducing the risk of infection.

After 5 years, the risk of developing cancer in other parts of the body, such as the mouth, throat, esophagus, and bladder, is reduced by about half.

After 10 years, the risk of lung cancer decreases significantly as the body repairs much of the damage caused by smoking, although not to the same extent as someone who has never smoked.

After 20 years, the risk of developing lung cancer is nearly the same as for someone who has never smoked, depending on individual factors such as overall health, age, and genetic predisposition.

Besides quitting smoking, the best way to prevent death from lung cancer is through regular screening. The majority of lung cancer cases are diagnosed at an advanced stage, resulting in a survival rate of only about 15%. Those recommended for lung cancer screening include individuals aged 50-80, those with a smoking history of 10 years or more, those who are still smoking, or those who have quit within the last 15 years.

If lung cancer is detected early, it can be cured through surgery. Therefore, even if you quit smoking 10, 20 years ago, or more, former smokers should still get screened for lung cancer, especially if they have risk factors.

Eating a balanced diet, maintaining physical activity, and avoiding exposure to secondhand smoke and other lung irritants can significantly reduce the risk of cancer.

People who experience symptoms such as persistent coughing, shortness of breath, chest pain, and coughing up blood should see a doctor immediately, as these are common symptoms of lung cancer.

According to vnexpress.net

Source: https://baophutho.vn/vi-sao-bo-thuoc-la-van-co-nguy-co-ung-thu-phoi-254649.htm