Histological Features and Tissue Microarray Taxonomy of Nigerian Breast Cancer Reveal Predominance of the High-Grade Triple-Negative Phenotype.

Pathobiology : journal of immunopathology, molecular and cellular biology

PubMedID: 26730581

Titloye NA, Foster A, Omoniyi-Esan GO, Komolafe AO, Daramola AO, Adeoye OA, Adisa AO, Manoharan A, Pathak D, D'Cruz MN, Alizadeh Y, Lewis PD, Shaaban AM. Histological Features and Tissue Microarray Taxonomy of Nigerian Breast Cancer Reveal Predominance of the High-Grade Triple-Negative Phenotype. Pathobiology. 2016;83(1):24-32.
INTRODUCTION
Little is known about the biology, molecular profile and hence optimal treatment of African Nigerian breast cancer. The aim of this work, therefore, was to characterize the histology and molecular profile of Nigerian breast cancer.

METHODS
Breast carcinomas from women at 6 centres of similar tribal origin in Nigeria were reviewed and assembled into tissue microarrays (TMAs), and sections were stained for hormone receptors, i.e. estrogen receptor (ER)a, ERß1, ERß progesterone receptor (PR) and androgen receptor, cyclin D, HER2, Ki67 and cytokeratins (CKs), i.e. CK5/6 and CK14 (basal) and CK18 and 19 (luminal).

RESULTS
A total of 835 tumours were analysed. The mean age at diagnosis was 48.62 ± 12.41 years. The most common histological subtype was ductal NST (no-special-type) carcinoma (87.3%). Over 90% of the tumours were grade 2 or 3. The predominant molecular phenotype was the non-basal, triple-negative type (47.65%) followed by the HER2-positive group (19.6%). The percentage of ER-, PR- and HER2-positive tumours was 22.4, 18.9 and 18.8%, respectively.

CONCLUSION
Nigerian breast cancer predominantly has a high-grade, triple-negative profile. It occurs at a younger age and bears similarities at the molecular level to pre-menopausal breast cancer in white women, with remarkably lower levels of ERß expression. The early presentation and histological and molecular phenotype may explain the poor prognosis, and tailoring treatment strategies to target this unique profile are required.