Concordance of immunohistochemistry for predictive and prognostic factors in breast cancer between biopsy and surgical excision: a single-centre experience and review of the literature

Abstract

Purpose Accurate evaluation of breast cancer on bioptic samples is of fundamental importance to guide therapeutic decisions, especially in the neoadjuvant or metastatic setting. We aimed to assess concordance for oestrogen receptor (ER), progesterone receptor (PR), c-erbB2/HER2 and Ki-67. We also reviewed the current literature to evaluate our results in the context of the data available at present. Methods We included patients who underwent both biopsy and surgical resection for breast cancer at San Matteo Hospital, Pavia, Italy, between January 2014 and December 2020. ER, PR, c-erbB2, and Ki-67 immunohistochemistry concordance between biopsy and surgical specimen was evaluated. ER was further analysed to include the recently defined ER-low-positive in our analysis. Results We evaluated 923 patients. Concordance between biopsy and surgical specimen for ER, ER-low-positive, PR, c-erbB2 and Ki-67 was, respectively, 97.83, 47.8, 94.26, 68 and 86.13%. Cohen’s κ for interobserver agreement was very good for ER and good for PR, c-erbB2 and Ki-67. Concordance was especially low (37%) in the c-erbB2 1 + category. Conclusion Oestrogen and progesterone receptor status can be safely assessed on preoperative samples. The results of this study advise caution in interpreting biopsy results regarding ER-low-positive, c-erbB2/HER and Ki-67 results due to a still suboptimal concordance. The low concordance for c-erbB2 1 + cases underlines the importance of further training in this area, in the light of the future therapeutic perspectives.

Digital Validation in Breast Cancer Needle Biopsies: Comparison of Histological Grade and Biomarker Expression Assessment Using Conventional Light Microscopy, Whole Slide Imaging, and Digital Image Analysis

“…Previous studies have consistently indicated that PR expression shows lower agreement than ER expression in assessing inter-observer variability [ 40 , 41 ]. PR is a target gene regulated by estrogen and naturally displays greater homogeneity in normal breast tissues and tumors [ 22 , 42 ]. Intermediate biomarker expression categories are less reproducible than categories at the extremes [ 43 , 44 ].…”

“…This process informs critical treatment decisions regarding potential neoadjuvant therapy before surgical interventions. In instances of complete pathological responses, the biopsy sample represents the sole remains of the available tumor [ 22 ]. Additionally, CNB samples are preferred over excision for biomarker testing because this approach helps to prevent many fixation problems [ 3 , 23 ].…”

Triple-Negative Breast Cancer Subclassified by Immunohistochemistry: Correlation with Clinical and Pathological Outcomes in Patients Receiving Neoadjuvant Chemotherapy

“…Immunohistochemistry (IHC) is an established laboratory method for evaluating the presence of antigens that is widely used in breast cancer and is pivotal for tailoring systemic treatments (e.g., the human epidermal growth factor receptor 2—HER2) [ 10 ]. Moreover, IHC is significantly less expensive and laborious than gene expression and has been evaluated in several studies as a surrogate marker of established intrinsic genomic-based subtyping assays, as summarized in Table 1 [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”

Development of an interpretable machine learning model for Ki-67 prediction in breast cancer using intratumoral and peritumoral ultrasound radiomics features

“…However, this primary method is invasive, time-consuming, and nonrepeatable. The inherent heterogeneity of BC results in a concordance rate between CNB and excision specimen, with a substantial variation ranging from 59-88% (5,6). Additionally, the inability of the traditional approach to dynamically evaluate Ki-67 changes during neoadjuvant therapy highlights its limitations (7).…”