Expression Patterns of ER, PR, Her-2/neu and p53 in Association with Nottingham Tumor Grade

Objectives: Histological grading has been an integral part of cancer diagnosis for a long time. Recent molecular studies show that breast cancer 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 personalized treatment. However, this may be unrealistic in the resource-limited parts of the world. Thus, we studied the expression pattern of hormone receptors and p53 tumor suppressor using immunohistochemistry (IHC) in breast cancer (BC) compared to the traditional tumor grade. Methods: Two hundred and five (n =205) cases were investigated. The Modified Bloom-Richardson score system was adopted in grading the tumors. Tissue sections of the cases were stained with specific primary antibodies (at dilutions of 1:60 for estrogen (ER) and progesterone receptors (PR), 1:350 for human epidermal growth factor (Her-2/neu), and 1:50 for p53. The Chi-square test was used to determine the association between the tumor grade and IHC markers. Results: Invasive ductal carcinoma of no-specific type (190 cases;92.7%) was predominant. Grade II tumor (n =146; 71.22%) was the most frequent. Hormone receptors (ER+; n =227 and PR+; n =145) had 62.0% and 70.7% positive cases; 34.2% (n =70) were positive for Her-2/neu, while 76.1% (n =156) were positive for p53. We observed strong 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). Conclusion: Nottingham grade has 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, hormone receptor, Nottingham grade, p53 mutation.