Decreased rate of benzo(a)pyrene-induced sister chromatid exchange in fibroblast cultures from patients with lung cancer.

Fibroblast cultures from 29 lung cancer patients including eight familial cases and from 25 healthy controls were investigated. We studied the benzprene-induced sister chromatid exchange (SCE) following incubation in the presence of 150 nM benzo(a)pyrene and found spontaneously increased SCE values in the patients' cells but a reduced response to benzprene as compared to the control cultures. The benzpyrene-induced SCE was positively correlated with both benzpyrene metabolism and DNA adducts in normal control cells but not in the patients' cells. The ratio of benzypyrene DNA adducts and benzpyrene-induced rate of SCE calculated for the individual cell strains exhibited a bimodal distribution with patients' cells, but not with control cells. We speculate that the described differences between patients' and control fibroblasts might reflect a genetic predisposition to the development of lung cancer in about one half of the patients tested.