Clinico-pathological Study of Breast Lesions with regard to E-Cadherin Immunoexpression as a Biomarker in Breast Cancer Tumorigenesis and Disease Progression

Abstract

Introduction- Proper histopathologic categorization of breast carcinomas has prognostic implications. Recent molecular profiling analysis of lobular compared with ductal cancers show E-cadherin mutation and loss to be a defining feature of lobular breast cancers, and suggest it to be a distinct molecular subtype of breast cancers. The majority of lobular carcinoma in situ and invasive lobular carcinomas have shown a complete loss of E-cadherin expression. E-cadherin loss explains the histopathologic appearance of lobular carcinoma in situ including a diffuse growth pattern of this non-gland-forming tumor with discohesive tumor cells. Material & Methods- The present study was conducted on 234 patients presenting with signs and symptoms of breast lesions. A detailed history and complete physical examination and preliminary investigations were recorded, followed by surgical intervention. Histopathology was done on formalin fixed and paraffin embedded tissue sections of breast lesions and subsequently immunostaining with ER, PR, HER2/ Neu and E-cadherin was performed. Results- Average age of patient's presentation in the study was 38.1±16.9 years. Two hundred and twenty one cases (94.4%) of breast lesions were seen in females and 13 cases (5.6%) in males, with Male: Female (M:F) ratio of 1:16. Out of the total 234 cases, 108 (46%) were diagnosed as benign and 126 (53.84%) cases as malignant. Out of the total of 126 malignant breast lesions, infiltrating ductal carcinoma (not otherwise specified) was the most frequently diagnosed lesion, comprising 67(53.2%) cases. Most of the cases, 120(95.0%) had a tumor mass. All the benign lesions showed strong and homogenous membranous positivity of E-cadherin with intensity score of 4+. Most of the Grade 1 infiltrating duct carcinomas showed E-cadherin 3+ proportion score with gradually decreasing score in higher grades. All the 6 cases (100%) of infiltrating lobular carcinoma were negative for E-cadherin. Infiltrating duct carcinomas with medullary features showed 1 case each of weak 1+ proportion score and 2+ Intensity score in < 10% of cells. E-cadherin scoring in benign and malignant cases was statistically significant (p value = 0.0169). Conclusions- E-cadherin expression can be used as diagnostic modality for the sub-typing breast cancers as Infiltrating duct or lobular carcinomas, if morphology is not clear, with a definite prognostic significance.