Incidence of cancer in the course of chronic pancreatitis

OBJECTIVE: Chronic pancreatitis patients appear to present an increased inc idence of pancreatic cancer. The aim of the study was to compare the incide nce of cancer, whether pancreatic or extrapancreatic, in our chronic pancre atitis cases with that in the population of our region. METHODS: We analyzed 715 cases of chronic pancreatitis with a median follow -up of 10 yr (7287 person-years); during this observation period they devel oped 61 neoplasms, 14 of which were pancreatic cancers. The cancer incidenc e rates were compared, after correction for age and gender, with those of a tumour registry. RESULTS: We documented a significant increase in incidence of both extrapan creatic (Standardized Incidence Ratio [SIR], 1.5; 95% confidence interval [ CI], 1.1-2.0; p <0.003) and pancreatic cancer (SIR, 18.5; 95% CI, 10-30; p <0.0001) in chronic pancreatitis patients. Even when excluding from the ana lysis the four cases of pancreatic cancer that occurred within 4 yr of clin ical onset of chronic pancreatitis, the SIR is 13.3 (95% CI, 6.4-24.5;p <0. 0001). If we exclude these early-onset cancers, there would appear to be no increased risk of pancreatic cancer in nonsmokers, whereas in smokers this risk increases 15.6-fold. CONCLUSIONS: The risks of pancreatic and nonpancreatic cancers are increase d in the course of chronic pancreatitis, the former being significantly hig her than the latter. The very high incidence of pancreatic cancer in smoker s probably suggests that, in addition to cigarette smoking, some other fact or linked to chronic inflammation of the pancreas may be responsible for th e increased risk. (C) 1999 by Am. Cell. of Gastroenterology.