CANCER IN THE OFFSPRING OF PARENTS WITH LUNG-CANCER

Despite several studies on the role of passive smoking in the developm ent of childhood cancer, particularly leukaemia, lymphomas and brain c ancer, no definitive answer has yet been provided. The aim of the coho rt study reported here was to analyse the incidence of cancer in the o ffspring of young lung cancer patients on the basis of the assumption that all of the offspring were exposed passively to smoke. The files o f the Danish Cancer Registry provided 3348 cases of lung cancer patien ts born after 1935, and their offspring (n = 6417) were identified thr ough the Danish Population Register. The files of the offspring were t hen linked with the files of the Danish Cancer Registry and the number s of cancers observed in the offspring were compared with those expect ed fi om national age-specific and calender-time-specific rates. A tot al of 135 333 person-years was the basis for analysis. Twenty-six canc ers were observed, with 30.3 expected, yielding a standardised inciden ce ratio (SIR) of 0.9 (90% confidence interval (CI), 0.6-1.2). There w as no excess of brain tumours, leukaemias or lymphomas. Stratification for sex of the lung cancer patients revealed a non-significantly incr eased risk for both non-Hodgkin's lymphoma (three cases; SIR = 3.4; 90 % CI: 0.9-8.7) and Hodgkin's disease (three cases; SIR = 2.6; 90% CI: 0.7-6.6) in the offspring of female lung cancer patients. These result s suggest that there is little evidence of an excess cancer risk in ch ildhood, whether due to passive smoking or to as yet unidentified gene tic factors, among the offspring of people who develop lung cancer. Ho wever, the results are limited by the fact that exposure was only asse ssed indirectly, with no measurement of actual cigarette consumption m ade. (C) 1997 Elsevier Science Ltd.