Research Article

Association Between Cancer Antigen 15-3 and Haematological Parameters According to Treatment Status in Nigerian Women With Breast Cancer

Abstract

Background: Cancer antigen 15-3 (CA 15-3), a circulating epitope of mucin-1 (MUC1), is used principally to support monitoring of breast cancer, whereas complete blood count indices reflect inflammation, marrow function and treatment-related toxicity. Treatment exposure can alter both marker systems, so the relationship between them may differ according to treatment status, and Nigerian data are limited. Aim: To determine the association between serum CA 15-3 and haematological parameters overall and within treatment exposed, newly diagnosed and healthy-control groups, and to describe CA 15-3 concentrations across the three groups. Methods: A hospital-based cross-sectional case-control study at the University of Port Harcourt Teaching Hospital enrolled 120 Nigerian women: 40 treatment-exposed patients (TG), 40 newly diagnosed treatment-naive patients (NG) and 40 apparently healthy controls (HC). Serum CA 15-3 was measured by enzyme-linked immunosorbent assay and a complete blood count panel on an automated five-part differential analyser. CA 15-3 was compared across groups by the Kruskal-Wallis test with Holm-adjusted Mann-Whitney pairwise comparisons, with one-way analysis of variance reported as a supportive analysis. Associations between CA 15-3 and each haematological parameter were assessed with two-tailed Spearman rank correlations using pairwise-complete observations (approximately 60 pooled, approximately 20 per group), with Benjamini-Hochberg false-discovery-rate (FDR) correction within each analysis family. Results: CA 15-3 differed among groups (H = 10.510, df = 2, p = 0.0052), with the highest median in newly diagnosed patients (158.50 U/mL; IQR 36.13-185.95) versus treatment-exposed patients (34.00; 14.85-121.05) and healthy controls (26.80; 22.98 30.75); only the newly diagnosed versus control contrast remained significant after Holm adjustment (p = 0.0019). In the pooled sample, CA 15-3 correlated positively with white cell count (WBC; ρ = 0.386; FDR p = 0.0433) and absolute neutrophil count (NEU#; ρ = 0.373; FDR p = 0.0433). Group-specific analysis concentrated these findings in treatment-exposed patients, in whom CA 15-3 correlated with NEU# (ρ = 0.654; FDR p = 0.0282), WBC (ρ = 0.644; FDR p = 0.0282) and red cell distribution width-CV (ρ = 0.622; FDR p = 0.0297). No correlation survived FDR correction in newly diagnosed patients or healthy controls. Conclusion: The pooled CA 15-3 associations with leucocyte and neutrophil counts were concentrated in treatment-exposed patients, whereas CA 15-3 concentrations were highest in newly diagnosed patients. Treatment status should be considered when interpreting CA 15-3 alongside routine blood-count indices. The findings are exploratory given the small group-specific samples and require confirmation in larger longitudinal studies.

Authors affiliation:

Mieiwari Ibifubara Jumbo: Department of Haematology and Blood Transfusion Science, Faculty of Medical Laboratory Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
Ebirien-Agana Samuel Bartimaeus: Department of Clinical Chemistry, Faculty of Medical Laboratory Science, Rivers State University, Nkpolu- Oroworukwo, Port Harcourt, Rivers State, Nigeria.
Evelyn Mgbeoma Eze (ORCID): Department of Haematology and Blood Transfusion Science, Faculty of Medical Laboratory Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
Zaccheaus Awortu Jeremiah: Department of Haematology and Blood Transfusion Science, Faculty of Medical Laboratory Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.

How To Cite: M.I. Jumbo, E.S. Bartimaeus, E.M. Eze, and Z.A. Jeremiah. Association Between Cancer Antigen 15-3 and Haematological Parameters According to Treatment Status in Nigerian Women With Breast Cancer. Current Research in Health Sciences, 4(2):48–59, 2026. https://doi.org/10.58613/crhs427