Prognostic biomarkers for colorectal cancer in a Nigerian population.

e15575 Background: Colorectal cancer (CRC) is a significant global health disease, with over one million new cases and more than 500,000 deaths in 2018. The incidence rate in Nigeria is 3.4 per 100,000 and the median overall survival is less than a year. More than 50% of patients present with metastatic disease and this has progressively worsened with no active routine national screening program in Nigeria. With an increasing burden of the disease there is a need to improve the prognosis and reduce the cancer related mortality from CRC. This study evaluates the prognostic value of cost-effective hematology/immunology biomarkers in the management of CRC in Nigeria. This prospective study aims to correlate hematology/immunology biomarkers with overall survival in CRC patients in a low resource setting. Biomarkers studied include neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), mean platelet volume (MPV), interleukin-6 (IL-6), and carcinoembryonic antigen (CEA). The study also assessed the utilization of these biomarkers to predict for advanced CRC (stages 3 and 4) at presentation. Methods: The study included 35 treatment-naïve CRC patients and 35 apparently healthy controls, with written consent obtained. Participants with CRC were clinically staged using the TNM staging AJCC UICC 8th edition. Baseline levels of biomarkers and plasma viscosity were measured and at 3- and 6-months post-treatment (surgery and/chemotherapy). Baseline levels for Serum IL-6 were measured only in participants with CRC. Data analysis included independent t-tests, Mann-Whitney U tests, and receiver operating characteristic curve analysis. Ethical approval was obtained from the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC) Ethics and Research Committee, Nigeria. Results: The median age was 53 years, with a male-to-female ratio of 3:2. Advanced CRC (stages 3 and 4) was present in 74.29% of patients. All biomarkers except MPV were significantly higher in CRC patients than controls (p < 0.001). Higher pretreatment levels of CEA, NLR, and PLR were associated with advanced CRC stages (p < 0.05). Baseline NLR and PLR cut off values of 1.47 and 124.56 predicted advanced CRC. Post-treatment, significant reductions were seen in CEA and plasma viscosity at 3 and 6 months, and in PLR at 3 months. Conclusions: Pretreatment levels of CEA, NLR, and PLR effectively identify CRC patients with poor prognosis. CEA is an independent predictor of overall survival. These biomarkers are cost effective tools for monitoring treatment response and for early identification of CRC with poor prognosis. This may help inform individualization of treatment in low resource settings.