Concordance of HER۲ Status between Core Needle Biopsy and Surgical Resected Specimens of Breast Cancer: A Narrative Review

Background & Objective: HER۲, a molecular biomarker, is routinely evaluated in breast cancer patients to guide therapeutic decisions. However, the concordance of HER۲ status between core-needle biopsy (CNB) and surgical specimen (SS) samples is not always high, potentially affecting the accuracy of diagnosis and treatment. This study aims to review recent studies assessing the agreement of HER۲ status between CNB and SS samples in breast cancer patients. Materials & Methods: A literature search was conducted in PubMed, Scopus, and Google Scholar databases from January ۲۰۱۸ to August ۲۰۲۳ using the keywords: concordance, core needle biopsy, resection, HER۲ status. Ten articles meeting the inclusion criteria were selected for this review. Results: The results demonstrated variable concordance rates of HER۲ status between CNB and SS samples, ranging from ۸۳.۳% to ۹۹.۵%. The primary factors influencing discordance were tumor heterogeneity, preoperative treatment, sampling error, and differing testing methods. Discordance was more prevalent in HER۲-negative and HER۲-low tumors compared to HER۲-positive tumors. Conclusion: The concordance of HER۲ status between CNB and SS samples is generally high but not perfect. Therefore, retesting HER۲ status on SS samples is recommended to ensure optimal treatment decisions for breast cancer patients.

Keywords:

Core needle biopsy , Surgical specimen , Concordance , HER۲