Lymphocyte-to-monocyte ratio predicts survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Lymphocyte-to-monocyte ratio (LMR) predicts overall survival (OS) in patients with colorectal cancer. We explored LMR in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). We identified all patients undergoing CRS/HIPEC for colorectal or appendiceal adenocarcinoma at our institution. We analyzed LMR's relationship with clinicopathologic variables with Kaplan-Meier log-rank survival analyses and multivariable Cox regression models with 5-year OS. Two hundred and sixteen patients underwent CRS/HIPEC. Five-year OS for low LMR (≤3.71) was 35.2 versus 60.4% for elevated LMR (hazard ratio [HR]: 2.0; 95% CI: 1.1-3.5; p = 0.02). On multivariable Cox-regression, elevated LMR was significantly associated with OS (p ≤ 0.05). LMR is an independent predictor of OS in patients undergoing CRS/HIPEC for colorectal and appendiceal adenocarcinoma.