IntroductionDespite the high mortality rate among colorectal cancer (CRC) patients in Africa, patients still bear the huge cost-related burden of cancer management. To reduce this burden, there is a current search for affordable markers for disease assessment and treatment monitoring. Contributing to this effort, this study evaluated systemic immune-inflammatory indices (SIII) among CRC patients.MethodsThis study included 89 patients with CRC diagnosed from Jan. 2016 to Dec. 2022. The patients were sub-grouped based on age and chemotherapy response. The neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), platelets-neutrophils-to-lymphocytes ratio (PNLR), and neutrophils-to-lymphocytes platelets ratio (NLPR) were assessed and analyzed accordingly. Significance was set at p< 0.05.ResultsThe median age of the patients was 58.0 years. Metastatic and stage III/IV CRCs were prevalent among patients older than 50 years compared with patients aged 50 years or less. Among patients aged > 50 years, the pre-treatment (pre-T) to post-treatment (post-T) total white blood cell count (TWBC), neutrophils, monocytes, and NLPR significantly increased whereas the post-T lymphocyte count and LMR significantly declined (p< 0.05). Post-T TWBC count and LMR of patients aged > 50 years were 1.5 times higher and 2.4 times lower, respectively compared with the post-T values of patients who were 50 years old or less (p< 0.05). The post-T PNLR/NLPR and LMR were 2.7/2.3 times higher and 4 times lower among chemotherapy-naïve patients compared with the post-T values of chemotherapy-experienced patients, respectively (p< 0.05). The post-T NLR, PLR, and PNLR among chemoresistance. patients were 2.4, 2.3, and 1.5 higher than the post-T values of chemosensitive patients at p= 0.027, 0.015, and 0.022, respectively.ConclusionThis study revealed a higher frequency of CRC and mortality risk among patients older than 50 years. It suggests that SIII could be used as a prognostic tool for CRC.