Family history of cancer and risk of lung cancer among nonsmoking Chinese women.

The relationship between family cancer history in first-degree relatives and risk of lung cancer was evaluated among a population-based cohort of 71,392 female nonsmokers in Shanghai, China. A total of 179 newly diagnosed lung cancer patients were identified during 441,410 person-years of follow-up. Lung cancer risk was not elevated among those with a family history of lung cancer. However, risk of lung cancer was increased among subjects who had two or more first-degree relatives with any type of cancers {rate ratio [RR], 1.95 [95% confidence intervals (95% CI), 1.08-3.54] for two relatives with any cancers and RR, 3.17 [95% CI, 1.00-10.03] for three or more relatives with any cancer}. Having a family history of colorectal cancer (RR, 2.38; 95% CI, 1.21-4.70) and having siblings with stomach cancer (RR, 2.16; 95% CI, 1.01-4.65) and pancreatic cancer (RR, 4.19; 95% CI, 1.04-16.95) were also found to be associated with lung cancer risk. This cohort study indicated a moderate association of lung cancer risk with a family cancer history in general, but not with a family history of lung cancer specifically. The associations were stronger when a sibling, rather than a parent, was affected. The apparent link between lung cancer risk and a family history of colorectal, stomach, and pancreas cancers may be worth further investigation.