Combination of Platelet Count and Mean Platelet Volume (COP-MPV) Predicts Postoperative Prognosis in Both Resectable Early and Advanced Stage Esophageal Squamous Cell Cancer Patients

The aim of this study is to search the most powerful prognostic factor from routine blood test for esophageal squamous cell cancer (ESCC) patients. Multiple laboratory tests were evaluated including those reflecting red blood cell parameters (hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and red blood cell distribution width (RDW)), platelet morphological parameters (mean platelet volume (MPV) and platelet count (PLT)), blood coagulation status (D-dimer), and tumor biomarker (CA19-9). Known inflammatory indices (NLR and PLR) were also calculated. A total of 468 patients who were diagnosed with ESCC between December 2005 and December 2008 were retrospectively analyzed in this study. By utilizing univariate and multivariate Cox proportional hazard analyses, we found that PLT and MPV were significantly associated with overall survival (OS) and disease-free survival (DFS) of ESCC patients, with optimal cutoff values of 212 and 10.6, respectively. Moreover, the combination of the preoperative PLT and MPV (COP-MPV) was calculated as follows: patients with both PLT (≥212 × 10(9) L(-1)) and MPV (≥10.6 fL) elevation were assigned a score of 2, and patients with one or neither were assigned a score of 1 and 0. The COP-MPV was an independent prognostic factor for OS (hazard ratio (HR) 0.378, 95 % confidence interval (CI) 0.241 to 0.593, P < 0.001, 0/2) and DFS (HR 0.341, 95 % CI 0.218 to 0.534, P < 0.001, 0/2) in multivariate analyses. In subgroup analyses for early (stages I and II) and locally (stage III) advanced stage patients, COP-MPV was found significantly associated with OS and DFS in each group (P = 0.025 and P = 0.018 for OS and P = 0.029 and P = 0.002 for DFS). In conclusion, we considered that COP-MPV is a promising predictor for postoperative survival in ESCC patients.