ABSTRACT
Patients who are cured of lung cancer are at increased risk to develop second primary tumors of the upper and lower respiratory tracts. Several prospective studies have shown that patients who continue to smoke after therapy of their initial cancer (including lung and head-and-neck neoplasms) have a higher risk of developing second primary tumors than do the patients who stop smoking. Epidemiological studies suggest that people who consume large amounts of fruit and vegetables have a lower risk of cancer. A possible explanation is that antioxidant vitamins contained in fruits and vegetables interfere with oxidative damage to DNA and lipoproteins, thereby preventing carcinogenesis. To date, however, the use of antioxidants has not been shown to lower the incidence of lung cancer.
