ABSTRACT
Genetic Factors Because only a fraction of individuals who smoke and only a portion of individuals ex posed to occupational carcinogens develop cancer, cancer susceptibility may have a ge netic basis. Several findings seem to support this theory. First, there is an increased risk of lung cancer in individuals with chronic obstructive pulmonary disease (COPD)—i.e., studies have shown that smokers with COPD have higher rates of lung cancer than smokers without COPD. Since the development of COPD appears to have a familial association, the increased risk of lung cancer may also involve a genetic risk. Second, lung cancer is more common in first-degree relatives. Third, increased metabolism of the antihyperten sive drug debrisoquine has been associated with an increased risk of lung cancer. It is suggested that individuals with increased oxidative activity may be at risk for developing cancer because of their increased level of activated carcinogens.
