A retrospective study of lung cancer in Bombay.

This is a retrospective study of 520 patients with lung cancer, seen at the Tata Memorial Hospital between 1963 and 1970. Matched controls were obtained from those patients who came to the hospital within the same period and who were diagnosed as not having cancer. The patients and controls were matched for age, sex and community. As reported in other studies, an association was found between smoking habit and lung cancer. The relative risk of all types of smokers to non-smokers is 2·45, of bidi smokers 2·64 and of cigarette smokers 2·23. There is a preponderance of the group of epidermoid carcinomata among smokers as against adenocarcinomata. The probable reasons for the reported low incidence of lung cancer in this population have been discussed.