Abstract
In order to elucidate risk factors of lung cancer according to histologic type, a casecontrol study was conducted on 101 pairs of lung cancer cases and their matched controls selected from 481 subjects through interviews by the author at Aichi Cancer Center Hospital from 1975 to 1981. The relative risks of smoking for Keyberg Group I (squamous cell, large cell, and small cell carcinoma) and Kreyberg Group II (adenocarcinoma) were estimated to be 7.0 and 1.3. Other risk factors revealed from this study were less frequency of bowel movement, history of asthma, and drinking milk (low) for Kreyberg Group I and occupational exposure such as to iron and other metals, large ratio of weight to height, and eating fruits (low) for Kreyberg Group II. The relative risks for the high and low risk factors obtained from a single factor analysis were confirmed by a multiple logistic regression analysis.
