Concordance of breast cancer biomarker testing in core needle biopsy and surgical specimens: A single institution experience

Abstract

Background Accurate diagnostic biomarker testing is crucial to treatment decisions in breast cancer. Biomarker testing is performed on core needle biopsies (CNB) and is often repeated in the surgical specimen (SS) after resection. As differences between CNB and SS testing may alter treatment decisions, we evaluated concordance between CNB and SS as well as associated changes in treatment and clinical outcomes. Methods We performed a retrospective analysis of breast cancer patients at our institution between January 2010 and May 2020. Concordance between CNB and SS was assessed for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Survival in patients, including recurrence, metastatic recurrence, and death, were assessed using chi‐squared likelihood ratio. Results In total, 961 patients met eligibility criteria. Concordance, minor discordance, total concordance (concordance plus minor discordance), and major discordance between CNB and SS were reported for ER (87.7%, 9.2%, 90.8%, and 2.9%), PR (58.1%, 29.1%, 87.2%, and 12.8%), and HER2 IHC (52.5%, 20.9%, 73.4%, 26.6%), respectively. HER2 FISH concordance and major discordance were 58.5% and 1.2%, respectively. Of major discordance, ER (48.2%, p < 0.001) and HER2 FISH (50.0%) led to more management changes than HER2 IHC (2.4%, p = 0.04) and PR (1.6%, p = 0.10). Patients with ER major discordance had increased risk of death (6.7% concordance vs. 22.2% major discordance, p = 0.004). Conclusion Overall, retesting ER and HER2 was more clinically beneficial than retesting PR. To aid decision‐making and minimize healthcare costs, we propose patient‐centered guidelines on retesting biomarker profiles.

Is Oncotype DX testing informative for breast cancers with low ER expression? A retrospective review from a biomarker testing referral center

“…Studies have repeatedly demonstrated an overall high concordance in ER IHC reporting between core biopsy and subsequent surgical specimens [ 26 , 27 ], however this has been challenged recently by a study showing high rates of ER negativity on surgical resections following core biopsies reported as ER-low [ 28 ]. Finally, there remain interpretive factors that may affect ER reporting, such as when pathologists fail to recognize decreased ER staining intensity in the internal control breast epithelium (if present), which can result in under-calling of both ER intensity and percentage.…”

Development and Assessment of a Novel Core Biopsy-Based Prediction Model for Pathological Complete Response to Neoadjuvant Chemotherapy in Women with Breast Cancer

“…Although p53 has not been included in international guidelines for the time being for the reasons mentioned above, there is a large consensus that studies on the efficacy of neoadjuvant chemotherapy (NAC) in BC have shown significantly higher pathological complete response (pCR) rates in tumors with p53 mutations compared to wild-type tumors [ 6 ]. Molecular profiling is routinely applied to pre-treatment core biopsy to assist in pre-operative management decisions, which is a vital reference when deciding whether to proceed with NAC treatment [ 7 ].…”