Influence of blood neutrophil to lymphocyte ratio on oncologic outcomes in peritoneal carcinomatosis of appendiceal origin.

Abstract

e14184 Background: The Neutrophil to lymphocyte ratio (NLR), a marker of systemic inflammatory response, is associated with prognosis in various cancers. The aim of this study is to evaluate the association of pre-operative NLR with oncologic outcomes in patients with appendiceal carcinomatosis. Methods: Clinico-pathological data were obtained from a prospectively maintained database of patients with appendiceal carcinomatosis who underwent cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemoperfusion (HIPEC) between 2001 and 2010. Pre-operative absolute neutrophil and lymphocyte counts were used to compute NLR, with elevated NLR defined a priori as >5. Logistic regression modeling and Kaplan-Meier analyses were performed on the available data. Results: 195 patients, with a median age of 54.5 years, underwent CRS and HIPEC. The median follow up time was 1.96 years. There were 41 patients (21%) who had elevated NLR preoperatively. Factors associated with overall survival (OS) were grade (p=0.01), simplified peritoneal cancer index (SPCI) (p=0.013), and age (p=0.02). In patients who did not undergo splenectomy at the time of CRS, elevated NLR, lymph node involvement, SPCI, age and pre-operative albumin were statistically significant predictors of OS on multivariable analysis. None of these factors were significant in patients who underwent splenectomy at the time of CRS. The 5-year overall survival was 57% vs. 31% in patients with NLR<5 compared to NLR>5 respectively (p<0.0001). Time to progression was 30 months compared to 14 months in patients with NLR<5 vs. >5 (p=0.001). Strikingly, the 5-year OS in patients with NLR<5 with or without splenectomy was 63% and 50% compared to patients with NLR>5 with or without splenectomy 37.5% vs. 23%, respectively (p=0.0001). Conclusions: In patients with appendiceal carcinomatosis, pre-operative NLR is a potential systemic inflammatory marker that independently predicts oncologic outcomes. The impact of NLR appears to be influenced by the performance of splenectomy at the time of CRS. Further studies will be required to prospectively validate this systemic inflammatory marker and its interaction with splenectomy.