ABSTRACT: OBJECTIVE: Tumor-associated macrophages are known to be associated with decreased survival of patients with endometrial cancer. Given the physiological link of circulating monocytes as a progenitor of tumor-associated macrophages, monocyte counts were examined for tumor characteristics and survival in endometrial cancer. METHODS: A retrospective study was conducted to examine consecutive patients with endometrial cancer with all histologic types who underwent hysterectomy-based surgical staging between 2003 and 2013 (n=541). Preoperative monocyte counts were correlated to patient demographics, pathological findings, complete blood count results, and survival outcomes. RESULTS: Median monocyte counts were 0.5×10(9)/L. Monocyte counts significantly correlated with all other complete blood count components, with neutrophil counts having the most significant association (r=0.52, p<0.001). Elevated monocyte counts (defined as >0.7×10(9)/L) when compared to lower counts were significantly associated with an increased risk of >50% myometrial tumor invasion (29.2% versus 22.0%, odds ratio [OR] 1.59, 95% confidence interval [CI] 1.01-2.45, p=0.045), pelvic lymph node metastasis (39.0% versus 18.8%, OR 2.76, 95%CI 1.35-5.62, p=0.007), and advanced-stage (stage I through IV, 18.5%, 24.6%, 32.5%, and 41.5%, p=0.001). In survival analysis, elevated monocyte counts were associated with decreased disease-free survival (5-year rates, 71.0% versus 84.5%, p=0.001) and overall survival (77.2% versus 89.3%, p<0.001). In multivariate analysis, elevated monocyte counts remained an independent prognostic factor for decreased disease-free (hazard ratio [HR] 1.74, 95% CI 1.02-2.96, p=0.041) and overall (HR 2.63, 95% CI 1.37-5.05, p=0.004) survival. CONCLUSIONS: Elevated monocyte counts were associated with aggressive tumor features and poor survival outcomes of patients with endometrial cancer.
