Preoperative combination score of neutrophils, monocytes, and lymphocytes as a predictor for locally advanced rectal cancer

Objective The aim of this study was to investigate the prognostic value of baseline peripheral blood neutrophils, monocytes, and lymphocytes on locally advanced rectal cancer (LARC) patients. Methods Clinicopathologic data of 317 LARC patients during July 2010 and October 2016 were retrospectively gathered. X-tile software was used to acquire the optimal cutoff values of neutrophils, monocytes, and lymphocytes. Peripheral blood immune score (PBIS) system was proposed and built based on neutrophils, monocytes, and lymphocytes. The Cox model was used to analyze the associations between clinicopathological characteristics and potential outcomes. C-index was used to assess model performance. A nomogram was constructed to predict prognosis, and a calibration plot was used to verify the accuracy of the nomogram prediction model. Results Cutoff values of neutrophils, lymphocytes, and monocytes were 4.46 (× 10 9 /L), 1.66 ( × 10 9 /L ), and 0.39 (× 10 9 /L), respectively. PBIS was related to sex ( P < 0.001), tumor length ( P = 0.003), and tumor thickness ( P = 0.014). Multivariate Cox regression analysis revealed that PBIS (HR = 0.707, 95% CI: 0.549–0.912, P = 0.008) was an independent predictor of DFS. High PBIS (HR = 0.697, 95% CI: 0.492–0.988, P = 0.043) and high lymphocyte count (HR = 0.511, 95%CI: 0.273–0.958, P = 0.036) were favorable factors of OS. Both C-index (0.74, 95% CI: 0.549–0.912) and the calibration plot showed good prediction ability of the nomogram for DFS. Conclusion PBIS, composed of baseline peripheral blood neutrophils, monocytes, and lymphocytes, is an independent predictor of the prognosis of LARC. Combination of PBIS and ypTNM stage may be a promising marker to guide adjuvant therapy after the operation.