Comparing Heat-Induced Antigen Retrieval Methods for ER Expression in Invasive Breast Carcinoma

In the realm of cancer diagnosis and treatment, immuno-histochemical staining has become a pivotal tool for discerning molecular markers within tissue samples. Objective: To comprehensively compare different heat-induced antigen retrieval methods for evaluating estrogen receptor (ER) expression in female invasive breast carcinoma of no special type. Methods: A cross-sectional design was employed utilizing 250 formalin-fixed paraffin-embedded (FFPE) tissue samples from confirmed cases of invasive breast carcinoma. The study was conducted within Histopathology Department in CMH Peshawar. The study spanned from January 6, 2022 to June 30, 2023. Three heat-induced antigen retrieval methods were evaluated: conventional microwave-based retrieval, pressure cooking retrieval, and water bath heating. ER expression was assessed through immune-histo-chemical staining, and scores were analyzed using descriptive statistics and ANOVA. A post hoc Tukey's Honestly Significant Difference (HSD) test was conducted to identify which specific retrieval methods exhibited significant differences in ER expression scores. Results: The pressure-cooking retrieval method exhibited significantly higher mean ER expression scores (7.52) compared to the conventional microwave-based (6.87) and water bath heating methods (6.65). Post hoc analysis confirmed the substantial differences. Standard deviations and interquartile ranges were consistent with each method. Conclusions: The study underscores the pivotal role of retrieval techniques in accurate ER expression assessment in female invasive breast carcinoma of no special type. The pressure cooking method emerges as a potent enhancer of ER expression, advocating for standardized protocols to ensure consistent diagnostic outcomes and informed therapeutic decisions. Despite limitations, this research contributes to the refinement of patient care in the management of invasive breast carcinoma.