Receptor Expression Discrepancy between Primary and Metastatic Breast Cancer Lesions

Abstract

SummaryBackground: Recent studies have shown that the expression status of hormone receptors and human epidermal growth factor receptor 2 (HER2) in breast cancer may change during disease progression. The aim of this study was to determine and compare the estrogen receptor (ER), progesterone receptor (PR), and HER2 expression status in primary breast cancer and metastatic lesions. Methods: 58 patients with registered biopsy reports or available samples of the primary tumor and distant metastases were included in the final analysis. Biopsy samples were re-stained using immunohistochemical methods to determine receptor status (if not already recorded in previous reports) and re-examined by 2 independent pathologists. Results: Discordance rates for receptor expression status of the primary tumor and distant metastases for ER, PR, and HER2 were 17.4, 45.4, and 13.3%, respectively. No statistically significant difference in overall survival due to receptor expression discordance between the primary tumor and metastatic sites (p > 0.05) was found, although a tendency toward worse survival time was observed in patients with HER2 expression discrepancies. Conclusion: This study showed receptor discordance rates between primary and metastatic breast cancer sites for ER, PR, and HER2 of 17.8, 45.4, and 13.3%, respectively. Re-biopsy and IHC evaluation of metastatic sites for receptor status may change treatment decisions in patients with relapsed/progressed BC.

Clinical Potential of Estrogen and Progesterone Receptor Imaging

“…Figure 3 is an example of one of the patients that switched from endocrine therapy to chemotherapy after a liver biopsy. These results are consistent with pathology studies where receptor discordance was found in approximately 15% of metastatic lesions compared to primary lesions (26, 27). In another case report study, temporal heterogeneity was seen in serial FES scans in a patient who was imaged at four time points: prior to initiation of endocrine therapy; after response to endocrine therapy; at subsequent disease progression on endocrine therapy; and at disease progression on chemotherapy (Figure 4).…”

Discordance of the estrogen receptor and HER-2/neu in breast cancer from primary lesion to first and second metastatic site

“…Better survival was demonstrated in patients with either primary or metastatic disease ER positivity compared to those with ER-negative disease. 14 , 16 , 17 However, survival advantage was not significant in all studies, 18 which may reflect on study size or duration of follow-up.…”

Fluorine-18 Labeling of the HER2-Targeting Single-Domain Antibody 2Rs15d Using a Residualizing Label and Preclinical Evaluation

“…Current methods for the determination of HER2 status, immunohistochemistry, and fluorescence in situ hybridization are invasive, requiring biopsy samples [6]. Furthermore, these techniques are of limited use for dealing with the heterogeneous nature of HER2 expression in the primary tumor and the significant discordance in HER2 expression in primary tumor and metastases as well as among metastases in an individual patient [7, 8]. In contrast, molecular imaging techniques such as positron emission tomography (PET) are noninvasive and can provide global status of HER2 in real time [9].…”