Breast cancer biomarkers at Niger delta university hospital: Comparisons with national and international trends and clinical significance

Abstract

Breast cancer biology is heterogeneous and patients with the same diagnostic profile have markedly different clinical outcomes. Gene expression profiling and its surrogate IHC markers classified breast cancer into four molecular subtypes with different prognosis, targeted therapies, and/or clinical outcomes. The present study was conducted to investigate breast cancer subtypes among women in NDUTH Bayelsa state and compared them with similar studies in other populations of international and national origin. Archived formalin fixed paraffin embedded tissue blocks were retrieved from January 2010-December 2014 provided 20 cases of microscopically confirmed invasive ductal breast carcinoma that were evaluable for histology and IHC (ER, PR, HER2, and Cytokeratin 5/6) immunostain. All the patients were females and most of them were under 50 years at presentation. The molecular subtypes were luminal A (54.1%), luminal B (25.0%), HER2 (12.5%), basal-like (4.2%), and unclassified (4.2%). Triple negative carcinoma (basal-like and unclassified combined) was 4.2%, ER+ (65%) and (PR+70%).Breast carcinoma in Bayelsa state women presents at a younger age. We note that the prevalence of the molecular subtypes of breast carcinoma appears to have variation in geographical distribution. The reasons for these differences could be technical, quality of fixation and processing, varying staining techniques, and different criteria in scoring and reporting. This study indicates that the majority of breast cancer in NDUTH lies at the two ends of the molecular spectrum, that is, luminal A (54.1%), sensitive to hormonal therapy and with a good prognosis, and "triple negative" (4.2%) not hormonally sensitive and with a poor prognosis.

Keywords: Breast cancer; IHC; Premier study; Surrogate.