Detection of DNA Mismatch Repair System in Carcinoma of Breast

Abstract

Objective: To correlate the immunohistochemical expression of MLH1 and PMS2 antibodies in carcinoma of breast.

Study Design: Descriptive study.

Place and Duration of Study: This study was conducted at the Department of Morbid Anatomy and Histopathology, Central Park Medical College Lahore from 1^st July 2016 to 31^st March 2017.

Materials and Methods: Ninety blocks of already diagnosed breast cancers were collected. The histological grading was done on conventional H&E, according to Nottingham grading system. For MLH1 and PMS2 labeling was done according to nuclear and cytoplasm staining.

Results: All the cases were of ductal invasive carcinoma.MLH 1 was found strongly positive in 51(56.7%) cases, weakly positive in 4 (4.4%) and negative in 35 (38.9%) of the cases and PMS2 was found strongly positive in 55 (61.1%) cases, while, weakly positive in 5 (5.5%) and negative in 30 (33.3%) of the cases.

Conclusion: Loss of expression of MLH1 and PMS2 reveals that microsatellite instability (MSI) has a role in the development of breast carcinoma.