Answer:

Cigarette smoke contains over 7,000 chemicals, including more than 70 carcinogens such as benzene, formaldehyde, and nitrosamine. These substances enter the body through the lungs, causing chronic inflammation, immune deficiency, and DNA damage, which can lead to cancer.

The WHO's International Agency for Research on Cancer (IARC) has identified at least 20 types of cancer linked to smoking, affecting the oral cavity, pharynx, esophagus, stomach, colon, rectum, liver, biliary tract, pancreas, nasal sinuses, larynx, and lungs.

Quitting smoking for five years, as you have, is a positive step that reduces the risk of cancer and other respiratory and cardiovascular diseases. According to the American Cancer Society, five years after quitting, the risk of mouth, throat, and larynx cancers can be halved. Damaged lung tissue begins to heal, and chronic inflammation decreases. Quitting for over 10 years can reduce lung cancer risk by 50%. The risk of esophageal, bladder, and kidney cancers also decreases proportionally to the time since quitting.

After 20 years of being smoke-free, the risk of certain cancers, such as mouth, throat, larynx, and pancreatic cancer, becomes nearly the same as for someone who has never smoked.

Esophageal cancer surgery for a long-term smoker. Illustrative photo: Tam Anh General Hospital

Quitting smoking as early as possible, especially before the age of 40, like you, offers many health benefits, including reducing the risk of other serious conditions such as heart disease, stroke, and chronic obstructive pulmonary disease (COPD).

In addition to quitting smoking, maintaining a healthy lifestyle, a balanced diet, regular exercise, stress reduction, and avoiding exposure to harmful substances can help prevent cancer and other serious diseases.

MSc. Dr. Vuong Ngoc Duong

Deputy Head of Radiotherapy Department

Tam Anh General Hospital, Hanoi