Evaluating malignant intraductal papillary mucinous neoplasm: A population-based study.

Abstract

324 Background: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas has been increasingly recognized. Due to a paucity of evidence, the management and treatment of IPMN is still under debate. We hypothesize that with increased awareness, the incidence and resection rates for IPMN would increase. Using a population-based cancer registry, we examined incidence, prognostic factors, and survival for IPMN. Methods: Patients diagnosed with invasive IPMN from 1988 to 2009 were identified by the Surveillance, Epidemiology, and End Results (SEER) database. Patient demographics, clinical and pathologic factors, and therapies received (surgery and/or radiation) were analyzed. Survival was assessed by Kaplan-Meier method; Cox proportional hazard modeling was used for multivariate analysis. Results: 2,987 patients were identified. Over the study period, there was a decrease in age-adjusted incidence. The overall resection rate was 20.6% with an increase in annual rates of resection. On univariate analysis, age greater than 65 years, tumor location, poorly differentiated tumor grade, higher T stage, and positive lymph nodes predicted worse survival; more recent diagnosis, higher number of lymph nodes examined, and surgery were indicators of improved survival. On multivariate analysis, curative surgery remained predictive of survival. Patients who underwent surgery had median survival rates of 87, 18, and 14 months compared to 6, 7, and 5 months in the no surgery group for stages I, II, and III, respectively. Conclusions: Although recent reports show increasing incidence of IPMN, our study involving a population-based cohort demonstrates decreasing incidence of malignant IPMN. This may be accounted for by increased detection of non-malignant disease. It is imperative that we identify patients with invasive IPMN early so that they may benefit from the survival advantage conferred by curative resection.