Prognostic significance of preoperative absolute peripheral monocyte count in esophageal squamous cell carcinoma

The objective of this study was to investigate the prognostic value of peripheral blood monocytes in esophageal squamous cell carcinoma (ESCC) patients who underwent esophagectomy. Records from 218 consecutive patients with histologically diagnosed ESCC who underwent esophagectomy at Qilu Hospital of Shandong University from January 2007 to December 2008 were retrospectively reviewed. The median disease-free survival (DFS) of this cohort was 29.0 months, and the 5-year DFS rate was 34.4%. The median overall survival (OS) was 35.0 months, and the 5-year OS rate was 37.6%. The cut-off value of 0.42 × 10⁹ /L for the absolute monocyte count (AMC) was chosen as optimal to discriminate between survival and death by applying receiver operating curve analysis. There were 131 patients (60.1%) who had high AMC (≥0.42 × 10⁹ /L) preoperatively. We found that AMC was significantly associated with gender, tumor location, and platelet count. Kaplan-Meier survival analysis of patients with high preoperative AMC had a significant worse prognosis for DFS (high vs. low: 27.5% vs. 39.0%, P = 0.015) and OS (high vs. low: 31.1% vs. 44.8%, P = 0.009) than those with low preoperative AMC. In a multivariate analysis, preoperative AMC was an independent prognostic factor for DFS (P = 0.025, hazard ratio [HR]: 1.469, 95% confidence interval [CI]: 1.050-2.054) and OS (P = 0.015, HR: 1.547, 95% CI: 1.088-2.200). In addition, among 140 patients without both preoperative and postoperative therapy, significantly worse OS (P = 0.012) and marginally reduced DFS (P = 0.079) were found in the high AMC cohort versus the low AMC cohort. A higher preoperative absolute peripheral monocyte count can be considered as a useful prognostic marker of ESCC patients who underwent esophagectomy.