Significance of monocyte counts on tumor characteristics and survival outcome of women with endometrial cancer

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 × 10⁹/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 × 10⁹/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.