Expression Patterns of ER, PR, HER-2/neu and p53 in Association with Nottingham Tumour Grade in Breast Cancer Patients

Abstract

Objectives: Recent molecular studies show that breast cancer (BC) is a heterogeneous disease, and several molecular changes may accumulate over time to influence treatment response. As a result, employing reliable molecular biomarkers to monitor these modifications may help deliver personalised treatment. However, this may be unrealistic in the resource-limited parts of the world. Thus, this study aimed to investigate the expression pattern of hormone receptors and p53 tumour suppressor using immunohistochemistry (IHC) in BC compared to the traditional tumour grade. Methods: In total, 205 cases were investigated, and the Modified Bloom-Richardson score system was adopted in grading the tumours. The tissue sections of the cases were stained with specific primary antibodies at dilutions of 1:60 for oestrogen receptors (ER) and progesterone receptors (PR), 1:350 for the human epidermal growth factor (HER-2/neu) and 1:50 for p53. Results: Invasive ductal carcinoma of no-specific type (n = 190, 92.7%) was predominant and grade II tumour (n = 146, 71.2%) was the most frequent. Hormone receptors ER (n = 127) and PR (n = 145) had 62.0% and 70.7% positive cases, respectively; 34.1% (n = 70) were positive for HER-2/ neu, while 76.1% (n = 156) were positive for p53. Significant associations between Nottingham grade and expression patterns of ER (P <0.01), PR (P <0.001), HER-2/neu (P <0.001) and p53 (P = 0.001) were observed. Conclusion: Nottingham grade had a high degree of concordance with the patterns of expression of hormone receptors, HER- 2/neu and p53, suggesting that it may play an important role in connection with the predictive and prognostic biomarkers for BC.

Keywords: Breast Cancer; HER-2/neu; Heterogeneity; Hormone Receptor; Oncoprotein p53.