Surgery for chronic pancreatitis decreases the risk for pancreatic cancer: A multicenter retrospective analysis

Background: Chronic pancreatitis is suggested to be one of the risk factors for the development of pancreatic cancer. The aim of this study was to confirm the high incidence of pancreatic cancer in patients with chronic pancreatitis in Japan and to determine the factors associated with the risk for pancreatic cancer in patients with chronic pancreatitis. Methods: The working group of the Research Committee of Intractable Disease supported by the Ministry of Health, Labour and Welfare of Japan carried out a nationwide survey to investigate the relationship between chronic pancreatitis and pancreatic cancer. This retrospective study included patients diagnosed with chronic pancreatitis who had had at least 2 years of follow-up. They were contacted through 22 Japanese referral centers experienced in the management of chronic pancreatitis. Results: The standardized incidence ratio (95 CI) of pancreatic cancer was 11.8 (7.1-18.4). The incidence of pancreatic cancer was significantly lower in patients who had received surgery for chronic pancreatitis than in those who had not undergone surgery (hazard ratio estimated by Cox regression 0.11; 95% CI, 0.0014-0.80; P = .03). Patients who continued to drink alcohol after diagnosis of chronic pancreatitis showed a significantly higher incidence of pancreatic cancer than those who stopped drinking after diagnosis of chronic pancreatitis (hazard ratio, 5.07; 95% CI, 1.13-22.73; P = .03). Conclusion: This study confirmed that chronic pancreatitis is an important risk factor for the development of pancreatic cancer in Japan. Patients who underwent surgery for the treatment of chronic pancreatitis had significantly lower incidences of pancreatic cancer. Surgery for chronic pancreatitis may inhibit the development of pancreatic cancer in patients with chronic pancreatitis.