Resection of primary pancreatic neuroendocrine tumors with concomitant liver resection: reasonable and safe

Abstract

Background: Pancreatic neuroendocrine tumors (PNETs) are increasing in incidence. Resection of liver metastases and the ideal timing of resection is a matter of debate. Combination pancreatic and liver surgery raises the concern of increased morbidity and mortality, however there is little data. The objective of this study was to determine whether or not there were differences in morbidity between resection of PNET primary alone versus concomitant resection of liver metastases. Methods: California Cancer Registry (CCR) was queried for patients with a confirmed histologic diagnosis of PNET with liver metastases who underwent resection from 2000 to 2012. The group was then divided into those who underwent resection of primary PNET alone with either a distal pancreatectomy (DP) alone, Whipple procedure (WP) alone, distal pancreatectomy with liver resection (DPLR), and Whipple procedure and liver resection (WPLR). Demographic, clinical, treatment characteristics, and hospital length of stay (LOS) were assessed with Cox proportional hazards. Complications were assessed using Fisher’s exact test. Results: 113 patients with PNET metastatic to the liver underwent resection with or without liver resection between 2000 and 2012. Of these 113 patients, 39 (34.5%) underwent DP alone, 40 (35.4%) underwent DPLR, 18 (15.9%) underwent WP alone and 16 (14.1%) underwent WPLR. There was no significant difference in demographics or disease characteristics between the groups who underwent primary resection alone vs. combined liver resection, including age, gender, race, comorbidities, primary tumor size, grade, or lymph node positivity. There was an increased LOS for those who had a combination DPLR compared to DP alone (7.48 days vs. 10.4 days, p = 0.02) but there was no difference in LOS between those who underwent WP vs. WPLR (19.6 days vs. 16.2 days, p = 0.64). There was no difference in overall complication rate between the groups. When broken down by complication type, there was no difference in intra-abdominal abscess rates between those who underwent DP vs. DPLR (p = 0.116) or those who underwent WP vs. WPLR (p = 0.900). There was also no difference in pancreatic fistula rates between those who underwent DP vs. DPLR (p = 0.494) or WP vs. WPLR (p = 1.00). Conclusion: PNETs are increasing in frequency, and current standard of care is to resect metastatic disease if complete resection is possible. Debulking surgeries are also noted as a consideration in NCCN guidelines with some evidence already published that debulking may improve survival. Using the CCR database, there was no difference noted in complication rates between removal of the primary alone versus concomitant liver resection; however, there were increased LOS with combination DPLR compared to DP alone.