Review : Epidemiological Studies Relating Family History of Lung Cancer to Risk of the Disease.

13 epidemiological case-control studies of lung cancer within families have been identified and analysed. A family history of lung cancer has been shown to be a lung cancer risk factor in 11 studies conducted in the US, Canada and the UK, with risk approximately doubled for those who have a relative with lung cancer. This effect, not evident in two Asian studies, could not be explained by the confounding effects of age, smoking habits, family size nor other variables, and recall bias can probably also be ruled out as an explana tion. The association was not specific to any type of relative nor type of lung cancer. It is probable that the association reflects differences in lung cancer risk between genotypes. If this is the case, the differences in risk between geno types would be much greater than 2-fold, since risk associated with family history markedly underestimates that attributable to the genotypes because not all family members would possess the relevant gene. [ABSTRACT FROM PUBLISHER]