THE RISK OF CANCER AT ALL SITES FOLLOWING GASTRIC OPERATION FOR BENIGN DISEASE - A COHORT STUDY OF 4,224 PATIENTS

This report represents the results of a historical cohort analysis of 3,360 males and 864 females who had a gastric resection or gastroenterostomy for benign disease between 1900 and 1969. Within the period 1970 to 1988 the cohort was cross-checked with the data files at the Cancer Registry of Norway to identify the patients in whom cancer had been diagnosed. When analyzed according to cancer sites, increased risk was recorded for the oropharynx, stomach, colon, pancreas, liver, biliary tract, larynx, lungs, urinary bladder and non-melanomatous cancers of the skin in males. In females, increased risk was only observed for the oropharynx, but was close to a statistically significant level also for cancer of the stomach. A lower number of tumors of the central nervous system than expected was observed in both males and females. The increased risk of cancer of the lungs, larynx and urinary bladder in males can be regarded as evidence of the high prevalence of smokers in the cohort. We suggest that the increased risk of cancer of digestive organs is mainly related to life-style factors, particularly tobacco-specific nitrosamines whose effect is enhanced by surgical sequelae.