Mucinous cystic neoplasms of the pancreas in the modern era. Experience with 707 patients

Abstract

Background: Mucinous Cystic Neoplasms are mucin producing cysts of the pancreas with malignant potential. The existing literature on treatment outcomes is limited to relatively small surgical series.

Methods: We reviewed the National Cancer Database assessing the outcomes of patients with mucinous cystic neoplasms between 2004 and 2016. Kaplan-Meier method and log rank test were used to make survival comparisons.

Results: A total of 707 patients were identified; 492(69.6%) underwent pancreatectomies. The majority of patients were women (71.4%), with median age 65 years (range: 22-90). Most common operation was partial pancreatectomy ie distal (48.4%) whereas 21.7% underwent a Whipple. Patients who were not operated were more frequently stage IV (40%) whereas patients who were operated had more frequently invasive adenocarcinoma (74.8%). Patients who underwent pancreatectomy had better survival compared to these who didn't undergo surgery (81.4 vs 6.6 months; p < 0.001). Comparing patients who underwent pancreatectomy and had invasive disease versus patients who had in situ disease the former were older (median age 62 vs 55.5 years p = 0.004) and more frequently men (26.1 vs 16.1%; p = 0.03), however they had similar tumor size (5.5 vs 7 cm respectively; p = 0.14) and similar tumor differentiation (moderately differentiated 50% vs 38.1%; p = 0.49). Patients with non-invasive (in situ) disease had prolonged survival compared to these with invasive disease (median OS not reached vs 50.2months; p < 0.001). After Cox proportional hazard regression nodal positive disease was the most important factor of decreased survival for invasive adenocarcinoma (HR: 2.2; p < 0.001).

Conclusion: Patients with adenocarcinoma arising from a mucinous cystic neoplasm of the pancreas have excellent survival when they undergo pancreatectomy especially if the disease is still in situ. However, 3/4 of patients who undergo resection have already developed invasive adenocarcinoma and nodal status dominates their prognosis. Advanced age but not the size of the cyst correlate with the presence of invasive disease.

Keywords: Invasive disease; Mucinous cystic neoplasms; NCDB; Pancreas; Treatment outcomes.