Neutrophil/lymphocyte ratio (NLR) predicts survival after curative treatments for rectal cancer patients

Inflammation presents a connection with tumorigenesis. Simultaneously, ionizing radiation causes tumour cell death and an immune response takes place. Patients’ baseline immune response can be a predictor of tumour response to rectal cancer treatments. Our aim was to evaluate the role of neutrophil-lymphocyte ratio (NLR) patient survival in rectal cancer. Patients, treatment, and survival data were retrospectively collected, concerning radiotherapy treatments administered with curative intent, from 2013 to 2017. Survival data were evaluated through Cox-analysis, log-rank and survival tables. For the 5-y overall (OS) and disease specific-survival (DSS), the discriminative cut-off NLR was estimated applying Area Under Curve (AUC), receiver operating characteristic (ROC), DeLong method. All analyses were performed using an IBM-SPSS v.25 and, for all, a level of significance α=0.05 was noted. 268 patients were included, with male prevalence (165, 61.6%), mean age at diagnosis of 64 y/o (SD=11.96), and 127 patients were aged 65 or above. The category was ECOG-PS 0 for 215 (80.2%), ECOG-PS1 for 48 (17.9%), and ECOG-PS2 for 5 (1.9%) patients. Anaemia at diagnosis was found in 111 (41.4%) patients. Diabetes was described for 51 (19%), heart disease 39 (14.6%), vascular disease 115 (42.9%), alcohol consumption 66 (24.6%), and smokers 88 (32.8%). Age-adjusted comorbidity index was 6 or higher for 92 (34.3%) patients. The tumour was located at the low rectum in 113 (42.1%), medium 71 (26.5%), and proximal 84 (31.3%) patients. The mean follow-up time was 34 months (SD=19.27). Regarding treatment approach, the most frequent was long-course neoadjuvant CRT (210, 78.4%), and the remaining were short course neadjuvant RT (27, 10.1%), adjuvant RT plus CHT (28, 10.4%), and adjuvant RT (3, 1.1%). Only 2 patients did not receive CHT. AUROC analysis showed the discriminative values of NLR>3.36 and NLR>3.36, for 5y-OS and 5y-DSS, respectively. Cox analysis revealed that patients with NLR above 3.36, were at higher risk for death related to rectal cancer [HR=2.07; 95%CI 1.04-4.14, p=0.039] and for all cause-death [HR=1.93; 95%CI 1.05-3.54, p=0.033]. The NLR cut-off estimated for our cohort (>3.36) was compared with other ones described in the literature (NLR>3.0). Eighty-two (30.6%) patients had NLR>3.36 and for 102 (38.1%) NLR was higher than 3. For those patients with NLR ≤3.36 and >3.36, the 5y-DSS was 79,2% and 46.3% [p(log-rank) 3.0, respectively. For the patients with NLR ≤3.36 and >3.36, the 5y-OS was 73.3% and 56.0% [p(log-rank) 3.0, respectively. Our data are in accordance with recent studies, affirming the predictive role of NLR for rectal cancer patients treated with curative intent. The AUROC discriminative value of NLR we found overwrites the existing reports in the literature. Regarding survival patterns, there were no significant differences between NLR>3.0 and NLR>3.6.