The role of ThinPrep cytology in the investigation of ki-67 index, p53 and HER-2 detection in fine-needle aspirates of breast tumors.

Purpose: The aim of the current study was to compare the immunocytochemical expression of ki-67, HER-2 and p53 on ThinPrep (TP)-processed smears, obtained by preoperative fine-needle aspiration (FNA) biopsies from primary breast carcinoma with the immunohistochemical results obtained on the corresponding surgical samples.
Methods: FNA biopsies were collected from 119 female patients during a 31-month period. Subsequently, these patients underwent surgical resection of the tumors.
Results: The overall accuracy (OA) of the TP cytology for ki-67, p53 and HER-2 expression was 96, 99 and 97%, respectively. There was a strong positive correlation between immunohistochemistry and immunocytochemistry results for ki-67 (Spearman's test 0.875) for p53 (Cramer's phi test 0.965) and HER-2 (Kendall's tau test 0.891).
Conclusion: This pilot study demonstrates that it is possible to monitor multiple molecular markers by using the TP cytology. 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 evaluation of ki-67, p53 and HER-2 expression is comparable to those of the histological evaluation, and could be of paramount importance for the preoperative planning of treatment.