Neutrophil lymphocyte ratio (NLR) as a predictive factor radiological response of neoadjuvant chemotherapy (NAC) in locally advanced rectal cancer (LARC)

Background: Resistance of Neoadjuvant Chemotherapy (NAC) in Locally Advanced Rectal Cancer (LARC) makes patients lose their therapeutic window for tumor resection oncologically. As one of the inflammatory biomarkers, Neutrophil Lymphocyte Ratio (NLR) has a significant role in tumor progression. This study aims to evaluate the NLR values as a predictive factor radiological response of NAC in LARC. Methods: This study used a cross-sectional study to assess the relationship of pre-chemotherapy NLR with NAC response. All subjects were LARC patients who underwent the NAC FOLFOX regiment at the Dr. Soetomo General Hospital from January 2016 to December 2020. Variables assessed in this study included tumor size (T), staging, pathology, metastasis status, Complete Blood Count (CBC) and abdominopelvic CT-scan examination before and after (3rd cycle) NAC FOLFOX regiment, after 3rd cycle NAC FOLFOX regiment, gender, and albumin level. Data were analyzed using SPSS version 23 for Windows. Result: A total of 102 LARC patients underwent NAC. There were 62 patients (60.8%) with low pre-chemotherapy NLR (<2.15) and 40 patients (39.2%) with high pre-chemotherapy NLR (> 2.15). There were 57 patients with a positive response to NAC (Complete Response (CR)/Partial Response (PR)), with 48 patients have low NLR (84.2%) and 9 patients (15.8%) with high NLR. There was a significant relationship between pre-chemotherapy NLR and type of histopathology (OR 11.810; 95% CI: 4.561-30.579; p<0.001) to the radiological response of NAC in the Chi-Square test. However, a logistic regression test found that the OR value of pre-chemotherapy NLR increased to 13.649 (95% CI: 4.266-43.671; p<0.001) to the radiological response of NAC. Conclusion: Pre-chemotherapy NLR can be used as one of the predictive factors of radiological response after the NAC FOLFOX regiment in LARC patients.