The aim of this study was to explore the most powerful systemic inflammation marker of survival in locally advanced rectal cancer (LARC) patients and construct prognostic nomograms. A total of 472 LARC patients undergoing neoadjuvant chemoradiotherapy (NCRT) and radical surgery from 2011 to 2015 were included. The optimal cutoff points for the systemic immune-inflammation index (SII); and neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR), and monocyte-to-lymphocyte (MLR) ratios were calculated and determined by using the X-tile program. The cut-off values were 797.6. 2.3, 169.5, and 0.4, respectively. Cox regression analysis demonstrated that higher pathological TNM stage, the AJCC tumor regression grade, and the NLR level were significantly associated with increased overall survival and disease-free survival. High NLR level (≥ 2.3) was associated with higher pre-NCRT CA19–9 levels, lower hemoglobin, larger tumor size, and more lymph nodes retrieved (p = 0.012, p = 0.024, and p < 0.001; p < 0.001, respectively). High NRL scores were associated with poorer 5-year disease-free survival and overall survival (p < 0.001, and p < 0.001, respectively). Predictive nomograms and time-independent receiver operating characteristic (ROC) curve that included the NLR score group were superior to those without NLR scores. Higher NLR scores (≥2 0.3) were associated with poorer DFS and OS in LARC patients. In addition, NLR was identified as the most effective marker for systemic inflammation, and the prognostic value was further confirmed by time-dependent ROC analysis. More intense adjuvant treatment could be considered for higher NLR score patients with LARC following NCRT.
