The role of ThinPrep cytology in the evaluation of estrogen and progesterone receptor content of breast tumors

Introduction: The objective of the current study was to analyze the potential value of immunocytochemical analysis on ThinPrep (TP) -processed smears, from fine needle aspiration (FNA) biopsies, of breast tumors for the determination of ER and PR content as compared with the immunohistochemical analysis performed on paraffin-embedded breast tumor specimens. Patients and methods: Percutaneous FNA biopsy of focal breast lesions in 119 female adult patients during a 31-month period was performed. Subsequently, these patients underwent surgical resection of the tumors. ER and PR status of the tumors was determined by immunocytochemical analysis on TP-processed smears and by immunohistochemical studies in paraffin-embedded sections. Results: With the use of TP technique adequate material was observed in all cases. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy (OA) of the TP technique for the ER were 98.95%, 100%, 100%, 95.84% and 99.15% respectively. In addition, sensitivity, specificity, PPV, NPV and OA of the TP technique for the PR were 100%, 87.5%, 95.60%, 100% and 96.64%, respectively. Conclusions: ER and PR status can be evaluated in FNA material from breast carcinomas by using the TP technique. Sample collection and storage is simple and permits the assortment of the FNA sample for both morphologic diagnosis and ancillary studies. The accuracy of TP technique in the detection of ER and PR content is comparable to those of the histological evaluation, and could be of paramount importance for the preoperative planning of treatment.