The role of cytoreductive surgery in patients with carcinomatosis from high-grade appendix cancer in the era of modern systemic chemotherapy.

4080 Background: Peritoneal carcinomatosis due to high-grade appendiceal neoplasm is optimally treated with cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) in selected patients. Systemic chemotherapy is often administered either prior or after surgery utilizing the same regimens applied in advanced colon cancer despite the very limited data to support such approach. The potential benefit of systemic chemotherapy in patients that underwent CRS and HIPEC was evaluated in this study. METHODS A retrospective analysis of patients with high-grade appendix cancer after CRS and HIPEC. Different chemotherapy regimens were evaluated. Overall survival (OS) and relapse free survival (RFS) were calculated using Kaplan Meier estimates. RESULTS From 150 patients with disseminated appendix cancer, 77 patients had high-grade disease and underwent their first CRS and HIPEC at our institution. The 5 years OS was 40.4 %, it was 52.7 % for patients with complete cytoreduction (CC) and 0 % for incomplete cytoreduction (P<0.001). Complete cytoreduction was achieved in 36/41 (88%) patients who underwent CRS within 6 months from diagnosis, while it was achieved in 22/36 (61%) patients if surgery was performed 6 months after diagnosis (P=0.009). The following OS and RFS were found among these chemotherapy groups (Table). CONCLUSIONS Complete cytoreduction is essential to achieve long-term survival. The use of systemic chemotherapy should not delay surgical intervention, since that hinders efforts for complete cytoreduction. Role of systemic chemotherapy is not well established and randomized clinical trials are needed in that regard. [Table: see text].