The effect of delay in fixation, different fixatives, and duration of fixation in estrogen and progesterone receptor results in breast carcinoma.

Accurate determination of estrogen receptor (ER) and progesterone receptor (PR) status in breast carcinoma is essential. Preanalytic variation may contribute to discordant results. Recently, American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) made recommendations to normalize fixation for breast biomarkers. To evaluate this, a 4-cm invasive lobular carcinoma was processed according to ASCO/CAP guidelines. The remainder was stored fresh at 4°C for 4 days and cut into biopsy-sized pieces. Each was fixed in 10% formalin, Pen-Fix (Richard-Allan Scientific, Kalamazoo, MI), Bouin solution, Sakura Molecular Fixative (Sakura Tissue-Tek Xpress, Torrance, CA), zinc formalin, or 15% formaldehyde for times ranging between 1 and 168 hours. Immunohistochemical studies for ER and PR were performed and interpreted. After 4 days at 4°C, all samples showed no degradation or ER/PR staining differences, except 2 Bouin-fixed samples, in comparison with the patient's sample processed according to ASCO/CAP guidelines. In our study, the preanalytic variables of fixative type, fixation time, and 4 days of ischemic time did not affect immunohistochemical accuracy for ER/PR.