Comparison Of P63 And Smooth Muscle Myosin Heavy Chain Immunomarkers In Distinguishing Invasive And Non-Invasive Breast Lesions – A One Year Observational Study

Abstract

Background: Breast malignancies are one of the leading reasons for increase in morbidity and mortality among women.(1) Majority of the cases are easily diagnosed based on histopathology but at times presence invasion is difficult to comment upon. Objectives: 1. To evaluate the efficacy of P63 and SMM-HC immunostaining in distinguishing invasive from non-invasive breast lesions. 2.To study the clinicopathological features of preinvasive and invasive breast lesions. Methodology: The present study was a prospective as well as retrospective study which included 30 cases from January 2017 to December 2018. Clinical details pertaining to the patient with breast carcinoma admitted to the tertiary care hospital were obtained from the case papers, and from the medical records department of the hospital. The details of the gross and histopathological findings were obtained from the requisition forms and report forms archived in the department of pathology. Tissues were kept for fixation in 10% formalin and processed, followed by paraffin embedding. Haematoxylin and Eosin (H&E) stained slides available from the department of pathology were studied for histopathological features. For Immunohistochemistry (IHC), Sections 4 to 5μ thick were placed on coated slides. The sections were stained with the antibody directed against P63 and SMM-HC, as per the IHC staining protocol. Result: Both P63 and SMM-HC were calculated to have similar sensitivity (94.74%) and specificity (93.33%). However, each had their limitations, P63 exhibited incomplete staining pattern whereas SMM-HC showed cross-reactivity with vascular smooth muscle cells (100%) and stromal myofibroblasts (40%). Conclusion: We have come to the conclusion that both the markers have very high sensitivity (94.74%) and specificity (93.33%). Both these markers could be used in conjuncture with each other to diagnose cases in which clear infiltrative morphology of invasive carcinomas is not apparent or the tumour margin is obscured as a result of inflammation.