Inflammatory Biomarkers and Histological Grade in Nigerian Women with Breast Cancer: A Cross-Sectional Study

Background: Chronic low-grade inflammation is increasingly recognized as a driver of cancer aggressiveness. However, studies linking soluble and cellular inflammatory indices to breast cancer morphological characteristics, such as histological grade in African women remain underexplored. This study aimed to determine the blood levels of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) at diagnosis and to assess their association with histological subtype and Nottingham histologic grade (NHG). Methods: A cross-sectional study was conducted at Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria, between January and December 2024. Consecutive women ≥18 years with treatment-naive, histologically confirmed invasive breast cancer were enrolled. Patients with prior malignancy, chronic inflammatory disease, or recent corticosteroid/NSAID use within two weeks were excluded. Serum hs-CRP, IL-6, and TNF-α were quantified by sandwich ELISA; NLR and PLR were derived from automated full blood count. Histological type and Nottingham grades were extracted from the histology report. Histological typing followed WHO 2019 criteria; grading used the Nottingham modification of Scarff–Bloom–Richardson. Non-parametric tests (Kruskal–Wallis, Spearman) were used to assess associations; p<0.05 was significant. Results: 92 eligible participants with a mean age of 52 ± 12.6 years were analyzed. Invasive ductal carcinoma of no special type constituted 98.9 % (91/92). NHG distribution was Grade 1: 4.3 %, Grade 2: 55.4 %, Grade 3: 40.2 %. Median biomarker levels were: hs-CRP 5.64 mg/L (IQR 3.14–8.24), IL-6 22.05 pg/mL (20.96–24.26), TNF-α 126.28 pg/mL (99.33–149.79), NLR 1.29 (1.09–1.52), and PLR 95.46 (71–114). hs-CRP, IL-6, and TNF-α exceeded normal reference limits; NLR and PLR remained within range. No significant differences in any biomarker were observed across NHG categories (hs-CRP p=0.64; IL-6 p=0.39; TNF-α p=0.84; NLR p=0.95; PLR p=0.61). Likewise, correlation coefficients between individual biomarkers and NHG were weak and non-significant (ρ=-0.11 to 0.10). Conclusion: Although systemic inflammatory biomarkers are universally elevated in newly diagnosed Nigerian breast cancer patients, they do not discriminate histological grade in this cohort. Larger, longitudinal studies incorporating molecular subtypes and outcome data are warranted before these indices can be adopted for prognostication in resource-limited settings.