Intraductal Papillary Mucinous Neoplasms of The Pancreas: A Nationwide Registry-Based Study.

BACKGROUND AND AIMS: To investigate the paraclinical and pathological features of surgically resected intraductal papillary mucinous neoplasms in Sweden.

MATERIALS AND METHODS: A review of prospectively collected data on patients undergoing pancreatic resection for a histopathologically verified intraductal papillary mucinous neoplasm between 2010 and 2016 was performed using the Swedish National Registry for Pancreatic and Periampullary Cancer.

RESULTS: A total of 3038 pancreatic resections were performed during the study period, of which 251 (8.3%) were due to intraductal papillary mucinous neoplasms. The intraductal papillary mucinous neoplasm cases comprised 227 noninvasive and 24 invasive lesions. There was an annual increase in the number of resected intraductal papillary mucinous neoplasms, from 13 in 2010 to 56 in 2016, and an increase in the proportion of intraductal papillary mucinous neoplasm to the total number of pancreatic resections (4.7%-11%). Biliary obstruction was the only independent predictor of invasive disease, with odds ratio 3.106 (p = 0.030). There was no difference in survival between low-, intermediate-, and high-grade dysplastic lesions (p = 0.417). However, once invasive, the prognosis was severely impacted (p < 0.001). Three-year survival was 90% for noninvasive intraductal papillary mucinous neoplasm and 39% for invasive intraductal papillary mucinous neoplasm. Survival was better in lymph node negative invasive intraductal papillary mucinous neoplasm (p = 0.021), but still dismal compared to noninvasive lesions (p < 0.001).

CONCLUSION: The number of surgically resected intraductal papillary mucinous neoplasms is increasing in Sweden. Biliary obstruction is associated with invasive disease. Low-to-high-grade dysplastic intraductal papillary mucinous neoplasm has an excellent prognosis, while invasive intraductal papillary mucinous neoplasm has a poor survival rate.