Abstract
Tobacco smoking accounts for at least 30% of all cancer deaths and nearly 90% of lung cancer deaths. Smoking cessation significantly reduces the risk of developing tobacco-related malignancies. Smoking after cancer diagnosis is also associated with multiple risks, including worse tolerance of treatment, higher risk of a failure and second primary tumors, and poorer quality of life. Apart from disease site and stage, continued smoking is considered the strongest adverse predictor of survival in cancer patients. However, the benefits of smoking cessation are undervalued: many patients are not aware of harms related to continued tobacco use after cancer diagnosis. Furthermore, health care professionals often do not encourage their patients to quit, and do not provide tobacco cessation assistance for continuing tobacco users. Despite the apparent impact of tobacco use on treatment outcomes, data on current smoking status is only rarely captured in clinical trials This article reviews the most important clinical aspects of smoking after the diagnosis of cancer.