THE EFFECTS OF CHEMORADIATION THERAPY ON THE IMMUNE CELL PROFILES OF ANORECTAL CANCER PATIENTS ATTENDING USMANU DANFODIYO UNIVERSITY TEACHING HOSPITAL, SOKOTO.

Abstract

Anorectal cancer remains an important cause of morbidity and mortality globally and in Nigeria, with most patients presenting at advanced stages requiring chemoradiation therapy (CRT). CRT combines fluoropyrimidine-based chemotherapy with pelvic radiotherapy and is known to influence immune function through bone marrow suppression and lymphoid depletion. This study evaluated the effects of two commonly used CRT regimens RDT/CAPOX and RDT/FOLFOX on immune cell profiles of anorectal cancer patients attending Usmanu Danfodiyo University Teaching Hospital, Sokoto. A prospective longitudinal design was employed. Pre- and post-treatment venous blood samples were analyzed using a SYSMEX KX-21N hematology analyzer to determine neutrophils, lymphocytes, monocytes, eosinophils, basophils, and MID cell counts. Paired samples t-tests assessed within-regimen changes, while independent samples t-tests compared immune responses between regimens. Findings showed statistically significant post-CRT reductions in eosinophils and basophils in both regimens (p < 0.05), indicating susceptibility of these granulocyte subsets to chemoradiation. Monocytes, neutrophils, lymphocytes, and MID cells showed no significant changes. Comparison between CAPOX and FOLFOX regimens revealed no statistically significant differences in their effects on all immune parameters (p > 0.05), demonstrating that both regimens exert comparable immunological impact. Overall, CRT produced mild but selective immune alterations, with no evidence of profound or regimen-specific immunosuppression. This study provides essential local evidence on the immunological effects of CRT in Nigerian anorectal cancer patients. The findings support the continued use of both CAPOX- and FOLFOX-based CRT protocols while highlighting the need for routine hematological monitoring and further research incorporating larger cohorts and detailed lymphocyte subset analysis.