Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio as Inflammatory Biomarkers in Colorectal Cancer at the University of Benin Teaching Hospital, South South Nigeria

This study evaluates the diagnostic and prognostic significance of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in colorectal cancer patients at the University of Benin Teaching Hospital (UBTH), Benin City, Edo State, South South Nigeria. Systemic inflammatory indices derived from routine full blood count data have emerged as accessible biomarkers for cancer prognosis, yet their evaluation in colorectal cancer has not been conducted in the South South Nigerian context. A case-control and follow-up cohort design enrolled 100 histologically confirmed colorectal cancer patients and 80 healthy controls. NLR and PLR were calculated from full blood count at diagnosis. Tumour staging, treatment modality, and 12-month survival outcomes were recorded. Median NLR was 4.8 in colorectal cancer patients versus 1.9 in controls. Median PLR was 178 versus 102 in controls. Both NLR and PLR were significantly elevated in cancer patients across all tumour stages. Elevated NLR (above 3.0) was associated with significantly reduced 12-month overall survival (hazard ratio 2.3, 95% CI 1.4 to 3.7) in multivariate Cox regression adjusting for stage, age, and treatment. PLR showed a similar but weaker prognostic association. NLR above 3.0 and PLR above 150 at diagnosis identified patients with a 2.6-fold higher risk of death within one year. The study recommends NLR as a routine prognostic tool at the time of colorectal cancer diagnosis at UBTH. Keywords: neutrophil-to-lymphocyte ratio, colorectal cancer, inflammatory biomarkers, prognosis, Benin City.