Comparison of core needle biopsy (CNB) and surgical specimens for accurate preoperative evaluation of ER, PgR and HER2 status of breast cancer patients.

The roles of core needle biopsy (CNB) have become well established as an important preoperative diagnostic method for breast lesions. We examined the concordance of histological types, nuclear grades, hormone receptors, and human epidermal growth factor receptor 2 (HER2) status between CNB and surgical specimens in 353 cases. In addition, we analyzed the correlation between the number of CNB specimens obtained and accuracy of histological factors in order to explore the optimal number of CNB specimens. Between CNB and surgical specimens, concordance rates of histological type, nuclear grade, estrogen receptor (ER), and progesterone receptor (PgR) status (cut-off 0-<1%, 1-10%, and 10%<), and HER2 were 84.4%, 81.3%, 92.9%, and 89.3%, respectively. In 52 of 353 patients who were histopathologically diagnosed as ductal carcinoma in situ (DCIS) by CNB, final diagnosis was changed in to invasive ductal carcinoma (IDC) in surgical specimens. Statistically significant differences were detected in the discrepancy of the following factors between CNB and subsequent surgical specimens: histological types, nuclear grade, and PgR, between patients who received four or more cores and those who had received three or less cores. In addition, a similar tendency was also detected in estrogen receptor (ER) and HER2 as in the above, and the cases that received four cores reached to 100% concordance in diagnosis between CNB and surgical specimens. Therefore, the optimal numbers of CNB were considered four at least in assessing the histological type, invasion, nuclear grade, hormone receptor status, and HER2 status of individual patients in the preoperative setting.