Different Molecular Subtypes of Invasive Breast Carcinoma

Yalpa Kumari; Farzana Memon; Bhawani Shanker; Syed Sohail Abbas Naqvi; Mohammed Salman Zafar

Yalpa Kumari MPhil Scholar, LUMHS Hyderabad
Farzana Memon HOD pathology depart BMC LUMHS Jamshoro
Bhawani Shanker Associate Professor of pathology, Muhammad Medical College Mirpurkhas
Syed Sohail Abbas Naqvi Associate Professor Pathology Khairpur Medical College
Mohammed Salman Zafar Associate Professor of Pathology Fazaia Ruth Pfau Medical College

Keywords: Breast cancer, p53, luminal B, Triple negative

Abstract

Objective: To evaluate the expression levels of p53 and determine the molecular subtypes of invasive breast carcinoma (IBC) using immunohistochemical methods, and the correlation between p53 expression and these molecular subtypes.

Methodology: This is cross-sectional descriptive was conducted at Department of Pathology, Liaquat University of Medical and Health Sciences, Jamshoro from July 2022 to December 2022. Specimens received in formalin as simple and radical mastectomy specimen, lumpectomy, excisional biopsy, wedge biopsy, were considered and kept in fixation for 24 hours. Standard protocols mentioned in Rosai and Ackerman’s Surgical Pathology were followed for grossing. For interpretation of p53 staining, cells with brown-yellow granules in the nucleus positive cells and after counting positive cells in 10 high-power fields (×400) of tumor cells the expression rate of H-score is <5% represented negative while the expression rate of H-score is >5% indicated positive. All the information was collected via study proforma and SPSS version 26 was used for data analysis.

Results: A total of 329 specimens were studied. Mean age of the patients was 45.53+12.10 years. Invasive ductal carcinoma was most common 93.9%. Grade III was most common 65.3%, grade II was 33.4% and grade I was 1.2%. Estrogen receptor was positive in 57.4% of the specimens, progesterone receptor was positive in 50.8% and HER2 positive in 54.1%. According to the frequency of the molecular subtypes of the specimens, HER2 was positive in 24.9%, luminal A was in 37.4% and luminal B was in 20.1%, while Triple negative was in 17.6% of specimen. Frequency of the P53 expressions was positive in 45.6% of the cases. Expressions of p53 according to molecular subtypes of invasive breast carcinoma was statistically significant (p=0.0001).

Conclusion: Aberrant expression of p53 was observed in triple-negative and HER2/neu-overexpressing tumors. A significant correlation was also found between p53 expression and the molecular subtypes of IBC. The elevated level of p53 expression in aggressive breast cancer phenotypes suggests that p53 may serve as a prognostic marker.