Trends and Outcomes of Cytoreductive Surgery with HIPEC for Appendiceal Cancer In US

Abstract

Introduction: Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy (CRS/HIPEC) has been increasingly being used in the treatment of appendiceal cancers with peritoneal dissemination. Our objective is to describe the trends in HIPEC use and its outcomes at a nationwide level. Methods: Stage IV appendiceal cancer patients who underwent CRC/HIPEC were reviewed from the National Cancer Database (period 2004-2017). Results: A total of 1592 patients were reviewed with steady increase in the number of reported cases over the study period. Mucinous adenocarcinoma was the predominant histology (84.5%), whereas 6% of patients had non-mucinous adenocarcinoma and 9.5% neuroendocrine/goblet cell/mixed histology tumors. The majority of procedures were performed at academic centers (71.8%) and this trend did not change during the study period (p = 0.6). Overtime, there was an increase in margin negative resections (2006: R0: 57.4%, 2017: R0:67.9%; p = 0.006), shorter hospitalizations (2006:14 days, 2017:9 days; p < 0.001), and no difference in the 90-day mortality rates: 2.8%. Survival was optimal for mucinous adenocarcinomas (median OS: mucinous adenocarcinomas:140.4mo vs 41.1mo for non-mucinous adenocarcinomas and 37.3mo for other (p < 0.001). Amongst mucinous adenocarcinomas presence of signet ring cells was associated with poor outcomes (OS: 29.2months vs 141.1mo for non-signet ring cell mucinous adenocarcinomas). Conclusion: The use of CRS/HIPEC has been increasing in the USA and is performed safely. It is being performed mainly at academic centers, with the best outcome for mucin producing tumors except in the presence of signet ring cells. With accumulating experience optimal cytoreductions have increased and hospitalizations have shortened over time.