Core Needle Biopsy Specimens Are More Appropriate than Surgical Specimens for Evaluating the Expression of Phosphoproteins as Biological Markers in Invasive Breast Cancer.

BACKGROUND/AIM: To evaluate whether core needle biopsy specimens (CNBS) would be better than surgical specimens (SS) for evaluating phosphoproteins as biological markers in breast cancer. MATERIALS AND METHODS: This retrospective analysis included a total of 99 patients who had invasive breast cancer and were treated surgically between January 2012 and July 2013. The expression of phosphorylated ribosomal protein S6-kinase-1 (p-S6K1), phosphorylated protein kinase B (p-AKT), and estrogen receptor (ER) were assessed immunohistochemically on both CNBS and SS for each patient. RESULTS: The expression rate of phosphoprotein at any intensity was higher on CNBS than on SS (p-S6K1, 99.0% versus 59.6%; p-AKT, 94.9% versus 56.6%). p-S6K1and p-AKT expression was classified as negativity (absence to weak staining) or positivity (moderate to strong staining) for further analysis. For p-S6K1, 24.2% of patients showed positivity on CNBS and negativity on SS, while 7% of the patients showed negativity on CNBS and positivity on SS. For p-AKT, 70.7% of the patients showed positivity on CNBS and negativity on SS, while only 1.0% of patients showed negativity on CNBS and positivity on SS. CONCLUSION: CNBS may be the more appropriate specimen type for immunohistochemical examination of phosphoprotein expression in invasive breast cancer.