Neutrophil-lymphocyte Ratio at the Beginning of Third-line Chemotherapy Seems to be a Useful Predictor for Unresectable Colorectal Cancer

Aim: This study aimed to evaluate a long-term outcome predictor after second-line chemotherapy for unresectable colorectal cancer.Methods: Between 2013 and 2018, sixteen patients (twelve males, four females) with unresectable colorectal cancer who were administered TAS-102 as third-line chemotherapy in our institution were retrospectively enrolled in this study. The mean age was 65.4 (range: 46-79) years. Patients were administered oxaliplatin with oral S-1 (tegafur, gimeracil, oteracil potassium) (SOX) as first-line chemotherapy followed by irinotecan with oral S-1 (IRIS) as second-line chemotherapy.Results: The median survival time after second-line chemotherapy was 19.2 months. Significant differences in mean age, gender, body mass index, primary site of disease, pathology of primary tumor, depth of primary tumor invasion, serum carcinoembryonic antigen (CEA) level, serum carbohydrate antigen 19-9 (CA19-9) level, and recurrence site of disease were not observed between patients with less than one year of survival versus greater than one year of survival. However, neutrophil-lymphocyte ratio (NLR) at the beginning of third-line chemotherapy was the only factor of the ten evaluated that exhibited a significant difference. Primary tumor site (p=0.015) and NLR at the beginning of third-line chemotherapy (p=0.010) were independent contributing factors to predict survival after second-line chemotherapy based on Cox proportional hazards regression.Conclusion: NLR at the beginning of third-line chemotherapy is a useful predictor for unresectable colorectal cancer after second-line chemotherapy.