Receptor discordance between primary and recurrent breast cancer
image: Eligible studies were original research papers that compared estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) receptor status in primary and recurrent breast cancer, published between 2013 and 2023, and written in English.
Credit: Kylie J. Mansfield
Background and objectives
Breast cancer is the most common cancer among women, with hormone receptors playing a crucial role, not only in cancer cell growth but also as primary targets in breast cancer treatment. This systematic literature review aimed to summarize the current evidence on estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) discordance rates between primary and recurrent breast cancer. Additionally, it seeks to identify how discordance affects prognosis, metastasis, and the potential evidence of primary tumor heterogeneity.
Methods
The databases Web of Science, Scopus, MEDLINE, and PubMed were searched for publications of original research in English from 2013 to 2023. Studies with paired histopathology from primary and recurrent breast cancer that employed immunohistochemistry and fluorescence in situ hybridization were included. Ten studies were deemed eligible for inclusion.
Results
Concordance between primary and recurrent breast cancer was high for ER (80%), PR (65%), and HER2 (85%). Average discordance rates were: ER 19%, PR 34%, and HER2 15%, with PR discordance consistently being the highest. Loss of ER and PR receptors was observed more frequently than gain, while the opposite trend was noted for HER2. Loss of ER and PR was associated with a worse prognosis. Discordance was also observed in cases of tumor metastasis.
Conclusions
Our study aimed to enhance the understanding of receptor discordance, its prognostic implications, and the evidence suggesting tumor heterogeneity in breast cancer. The discordance rates observed between primary tumors and metastatic sites were consistent with the loss of hormone receptor expression, suggesting the emergence of resistant tumor clones. Authors of the included studies found that patients with a loss of ER and PR had a worse prognosis, while those with receptor gain responded well to treatment changes, leading to a better prognosis. Our study highlights the need for further research to fully comprehend the implications of tumor heterogeneity and receptor discordance. A deeper understanding of these factors could significantly impact the treatment and prognosis of breast cancer patients.
Full text
https://www.xiahepublishing.com/2996-3427/OnA-2024-00027
The study was recently published in the Oncology Advances.
Oncology Advances is dedicated to improving the diagnosis and treatment of human malignancies, advancing the understanding of molecular mechanisms underlying oncogenesis, and promoting translation from bench to bedside of oncological sciences. The aim of Oncology Advances is to publish peer-reviewed, high-quality articles in all aspects of translational and clinical studies on human cancers, as well as cutting-edge preclinical and clinical research of novel cancer therapies.
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