LOBE OF ORIGIN OF LUNG-CANCER AMONG ASBESTOS-EXPOSED PATIENTS WITH ORWITHOUT DIFFUSE INTERSTITIAL FIBROSIS

The effect of asbestos exposure and asbestos-associated fibrosis on th e lobe of origin of lung cancer was studied among 108 lung cancer pati ents. The asbestos-exposed patients had significantly more lower lobe tumors than the unexposed patients. Similar results were obtained when occupational history or lung fiber concentration was used as an indic ator of past occupational exposure to asbestos. The predominance of lo wer lobe tumors occurred even among exposed patients with no histologi cal signs of asbestosis in their lung specimens. Both bronchial and pe ripheral cancers showed a lower lobe predominance among the exposed pa tients. Smoking history did not affect the lobar distribution of the t umors. No significant differences occurred for the histological cell t ypes of the tumors between the exposed and unexposed patients. Patient s with asbestosis had, however, more adenocarcinomas than the unexpose d patients. The results indicate that asbestos may increase the risk o f lung cancer even in the absence of asbestosis.