Comparative Analysis of Immunohistochemistry of Hormone Receptors in Breast Cancer by Conventional and Microwave Tissue Processing Methods

Abstract

Introduction: Rapid histopathological processing of neoplastic biopsies is crucial for initiating early therapy in patients. Microwave processing shortens the time to diagnosis and is less labour intensive. Aim: To compare the quality of immunohistochemical staining of Estrogen Receptors (ER) and Progesterone Receptors (PR) on paired breast samples using microwave processing versus conventional processing. Materials and Methods: A cross-sectional study was conducted at a tertiary care hospital in Kerala, India, from February 2014 to September 2015. A total of 44 paired samples from breast carcinoma patients were taken. Baseline characteristics of the patients such as age and type of carcinoma were noted. Haematoxylin and Eosin (H&E) stain was used. One slide of the pair was processed conventionally and the other using a microwave. The stained slides were observed by three pathologists. The validity of ER and PR receptor status was evaluated with sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV). Kappa statistics and Spearman’s correlation test was used to denote the agreement between them. Results: The mean age was 51.32±11.16 years. There was agreement (Cohen k=0.902) between the microwave processed and conventionally processed paired breast samples for ER. The sensitivity and specificity of microwave processing in ER evaluation was 87.5% and 100% while that of PR evaluation was 92.9% and 100% respectively. The PPV was 100% and NPV was 93.3% for ER evaluation by microwave processing. Conclusion: Microwave aided tissue processing had significant advantages over conventional methods for providing a rapid diagnosis, being less laborious and had effective staining, which makes it a better choice.