Spectrum of Breast Carcinoma in Relation to ER, PR and HER2/neu Status with Special Emphasis on Changing Patterns in Recurrence

Abstract

Introduction: Breast carcinoma is the most common malignant tumour and the leading cause of carcinoma death in women, worldwide. The immunohistochemical classification provides both therapeutic and prognostic information. Aim: To classify breast carcinoma according to molecular subtype and to know the association between molecular classification and clinicopathological parameters of prognostic significance. Also, to look for changes in Immunohistochemistry (IHC) pattern and lymph node status in case of recurrence. Materials and Methods: A prospective study conducted in the Department of Pathology in association with Department of General Surgery in Institute of Post Graduate Medical Education and Research, Kolkata, West Bengal, India (January 2014 to June 2015) was done on 50 cases. Patients undergoing mastectomy for breast carcinoma and reoperated for recurrent mass were selected. Haematoxylin and Eosin (H&E) staining and IHC staining were done. The specimens were classified according to IHC staining into molecular subtypes and these were correlated with clinicopathological features. IHC study was also done on recurrent masses following surgical removal. All statistical tests were performed using software IBM SPSS statistics version 20.0. Significance p-value was considered at <0.05. Results: Maximum cases 25 (50%) were luminal A, followed by 11 (22%) Human Epidermal Growth Factor 2 (HER2)/neu, 9 (18%) were luminal B and 5 (10%) were triple negative or basal type. Among 50 patients only five patients developed recurrent mass. Among the five patients who developed recurrence, the initial lymph node status was as followsN0-0 patient, N1-1 patient, N2-3 patients and N3-1 patient. All the five patients who had recurrence initially had grade III tumour (p-value=0.0007). Surgical margin was involved in five patients of which two patients developed recurrent mass (p-value=0.02). As the gradation of carcinoma increased, their IHC pattern also changed from luminal A to luminal B to HER2/ neu to basal type. Conclusion: It was found that luminal A and luminal B subtype have relatively favourable prognostic significance than HER2/ neu and basal subtype. IHC subtypes are also proportionate with Nottingham combined histological grading system.

Keywords

• immunohistochemistry
• molecular classification
• triple negative