Systemic inflammation-based predictors of pathological response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer patients: A propensity score matching analysis

Abstract

Background: In the management of locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT), the relationship between systemic inflammation-based predictors and tumor response remains unclear. This study aimed to determine whether these inflammatory factors can predict tumor response.Methods: Totally 205 LARC patients underwent neoadjuvant CRT and curative surgery between 2008 and 2017 were analyzed. After propensity score matching, 146 patients (73 matched pairs) were enrolled in this study. The hematological parameters were collected and their relationship with tumor response was investigated.Results: After propensity score matching, the neutrophil-lymphocyte-ratio (NLR) and platelet-lymphocyte-ratio (PLR) before CRT in good response group were significantly lower than those in poor response group, while there was no significant difference in all hematological characteristics between two groups after CRT. The cutoff values​​ of pre-CRT NLR and pre-CRT PLR were 3.10 and 198.7 after receiver operating characteristic analysis. Multivariate analysis model indicated that pre-CRT PLR was not related with tumor response, while pre-CRT NLR≥3.1 was the predictor of poor tumor response (OR=2.047, 95%CI =1.241-3.377, p=0.005). Besides, patients with NLR≥3.1 had a significantly poor tumor regression grade rates compared with patients with NLR<3.1 (p=0.036).Conclusion: The increased NLR before CRT can be regarded as a hematological factor for poor tumor response in LARC, and higher NLR also represents worse tumor regression grade.