Pattern of hormone receptors and human epidermal growth factor receptor 2 status in sub-Saharan breast cancer cases: Private practice experience

Breast cancer is the most common cancer among women globally. With immunohistochemistry (IHC), breast cancer is classified into four groups based on IHC profile of estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2/neu) expression, positive (+) and/or negative (-). The IHC classification correlates well with intrinsic gene expression microarray categorization. ER-positive tumors may benefit from being treated with selective ER modulators and aromatase inhibitors, whereas patients with HER2/neu positive tumors have been shown to experience a significant survival advantage when treated with humanized monoclonal antibodies against HER2/neu. To determine ER/PR, HER2/neu expression and their association with histological prognostic markers in female breast carcinomas seen in a private diagnostic laboratory based in Lagos. Immunohistochemistry reports of breast cancer patients, which were diagnosed by histopathology section of a private diagnostic laboratory based in Lagos, Nigeria from August 2009 to August 2014. About 18.7% of breast cancers had IHC (ER, PR and HER2) done on them and were all females. The mean age of all subjects was 49.5 years (standard deviation, 13.2; range, 29-78 years). Most (95.8%) of the breast cancers were of invasive ductal carcinoma type, with 77.4% of them been >5 cm. IHC pattern was as follows: ER/PR+, HER2-=19 (39.6%), ER/PR-, HER2- (triple negative [TN])=14 (29.2%), ER/PR+, HER2+=9 (18.8%), ER/PR-, HER2+=6 (12.5%), corresponding to Lumina A, TN/basal-like, Lumina B and HER2 over expressed respectively. Triple negative breast cancers are common in our environment and affect young females most and could be contributory to the poorer prognosis of breast cancer in our environment.