The Predictive Role of Circulating Inflammatory Biomarkers in the Response to Cetuximab-Based Therapy for unresectable stage IV Metastatic Colorectal Cancer

Background:The purpose of our retrospective study was to evaluate the role of inflammatory biomarkers to predict response to 5-fluorouracil/folinic acid and Cetuximab in patients with unresectable stage IV metastatic colorectal cancer (mCRC). Material and Methods: We conducted a retrospective study of 38 patients with stage IV metastatic colorectal cancer (mCRC) who underwent first-line therapy (FOLFOX/FOLFIRI Doublet Chemotherapy + Cetuximab) between 2014 and 2023. The inclusion criteria were: KRAS wildtype status, left-sided colorectal cancer, and a CT scan response assessment within three months from starting treatment. The chemotherapy response was evaluated using RECIST 1.1 criteria. The Neutrophil-to Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) were measured one day before treatment. A ROC curve analysis was used to determine cutoff values that would predict which patients would be responders (complete or partial response) or non-responders (stable or progressive disease). Results: ROC curve analysis identified cutoff values of 1.54 for NLR (Neutrophil-to-Lymphocyte Ratio) and 95.90 for PLR (Platelet-to-Lymphocyte Ratio). Higher levels of lymphocytes were associated with more favorable responses to treatment, whereas elevated neutrophil and platelet counts were linked to poorer outcomes. Conclusion: Our study describes the significance of Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) as predictive biomarkers in Cetuximab based treatment for unresectable metastatic colorectal cancer (mCRC).