Evaluating the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as prognostic and treatment response biomarkers in stage IV colorectal cancer patients

Introduction. Stage IV colorectal cancer presents significant challenges in prognosis and treatment response. Reliable biomarkers are critical for predicting outcomes and guiding treatment choices. This study evaluated the efficacy of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as such biomarkers. Material and methods. Conducted at a hematology department in Mashhad, Iran, this study involved 105 patients diagnosed with stage IV colorectal cancer. Participants underwent complete blood count analysis before chemotherapy to determine the NLR and PLR. Clinical information was collected, including tumor size, location, and KRAS/NRAS/CEA levels. Post-treatment categorization followed the RECIST guidelines. Results. Median values for the NLR and PLR were 4.8 and 169.0, respectively. A higher NLR and PLR were significantly associated with progressive disease post-treatment. ROC analysis demonstrated the prognostic accuracy of the NLR (AUC 0.95) and PLR (AUC 0.90) at specific cutoffs. These markers also showed predictive accuracy for treatment response. Correlation analysis indicated a strong positive correlation between initial and post-treatment CEA levels and both the NLR and PLR. Conclusions. The NLR and PLR are significant predictors of clinical outcomes in stage IV colorectal cancer, with potential utility in routine clinical practice for prognosis and treatment response prediction. Their high sensitivity and specificity suggest a role in guiding clinical decision-making. Further research is needed to refine their application in CRC management.