PANCREATITIS AND THE RISK OF PANCREATIC-CANCER

Background. The results of case-control studies and anecdotal reports suggest that pancreatitis may be a risk factor for pancreatic cancer, but there have been no studies of sufficient size and power to assess the magnitude of the relation between these two diseases. Methods and Results. We undertook a multicenter historical cohort study of 2015 su bjects with chronic pancreatitis who were recruited from clinical cent ers in six countries. A total of 56 cancers were identified among thes e patients during a mean (+/-SD) follow-up of 7.4+/-6.2 years. The exp ected number of cases of cancer calculated from country-specific incid ence data and adjusted for age and sex was 2.13, yielding a standardiz ed incidence ratio (the ratio of observed to expected cases) of 26.3 ( 95 percent confidence interval, 19.9 to 34.2). For subjects with a min imum of two or five years of follow-up, the respective standardized in cidence ratios were 16.5 (95 percent confidence interval, 11.1 to 23.7 ) and 14.4 (95 percent confidence interval, 8.5 to 22.8). The cumulati ve risk of pancreatic cancer in subjects who were followed for at leas t 2 years increased steadily, and 10 and 20 years after the confidence interval, 1.0 to 2.6 percent) and 4.0 percent (95 percent confidence interval, 2.0 to 5.9 percent), respectively. Conclusions. The risk of pancreatic cancer is significantly elevated in subjects with chronic p ancreatitis and appears to be independent of sex, country, and type of pancreatitis.