BACKGROUND AND OBJECTIVEFourty years ago, Tokuhata and Lilienfeld provided the first epidemiologic evidence of familial aggregation of lung cancer. Familial aggregation and increased familial risk for lung cancer have been reported in several studies, subsequently. But the results are not consistent with each other. The aim of this study is to further explore the relationship between family history of lung cancer and lung cancer risk.

METHODSBy searching PubMed, CENTRAL, CBM, CNKI and VIP, we collected both domestic and overseas published documents before November, 2009 on family history of lung cancer and lung cancer risk. RevMan version 4.2 was used to perform meta-analysis on the case-control study results, the combined odds ratio (OR) and the 95% confidence interval (CI) were calculated as well.

RESULTSTwenty-eight publications were included into the combined analysis, which indicated that the lung cancer risk of the probands' first-degree relatives was 1.88 times higher than that of their controls' (P < 0.001). In the sub-study, compared with the controls' father mother and siblings, the OR of the probands' father mother and siblings was 1.62 (P < 0.001), 1.96 (P < 0.001) and 1.92 (P < 0.001), respectively. For smoking status, lung cancer risk in first-degree relatives of smoking probands was 1.73 (P < 0.001) times higher than that of their corresponding controls'. And for non-smoking subjects the lung cancer risk was 1.42 (P = 0.02) times higher in proboands' first-degree relatives. For gender categories, lung cancer risk in first-degree relatives of female probands was 1.89 (P < 0.001) times higher than that of their corresponding controls'. And for male subjects, the lung cancer risk was 1.99 (P < 0.001) times higher in proboands' first-degree relatives.

CONCLUSIONLung cancer risk was increased in probands' first-degree relatives, and obvious familial aggregation of lung cancer was observed in this study.