Potential Clinical Utility of Serum HER-2/neu Oncoprotein Concentrations in Patients with Breast Cancer

Abstract

Background:The HER-2/neu oncogene and its p185 receptor protein are indicators of a more aggressive form of breast cancer. HER-2/neu status guides Herceptin therapy, specifically directed to the extracellular domain (ECD) of the HER-2/neu oncoprotein. The HER-2/neu ECD is shed from cancer cells into the circulation and is measurable by immunoassay. Methods: We performed a systematic review of the peer-reviewed literature on circulating ECD with respect to prevalence, prognosis, prediction of response to therapy, and monitoring of breast cancer. Results: The prevalence of increased ECD in patients with primary breast cancer varied between 0% and 38% (mean, 18.5%), whereas in metastatic disease the range was from 23% to 80% (mean, 43%). Some women with HER-2/neu-negative tumors by tissue testing develop increased ECD concentrations in metastatic disease. Increased ECD has been correlated with indicators of poor prognosis, e.g., overall survival and disease-free survival. Increased ECD predicts a poor response to hormone therapy and some chemotherapy regimens but can predict improved response to combinations of Her-

Cancer biomarker HER-2/neu in breast cancer in Indian women

“…HER-2/neu has been extensively studied in breast cancer, and approximately 20%-30% of patients have tumors that overexpress this receptor, often as a result of gene amplification. 10 Amplification of HER-2/neu gene is regarded as an established predictive and prognostic cancer biomarker for breast cancer, particularly for the management of advanced breast cancer. 11 We undertook this study to evaluate the serum HER-2/neu levels in normal healthy individuals, individuals with benign breast disease, and untreated breast cancer patients, and tried to associate these levels with other prognostic factors such as age, menopausal status, stage of disease, node involvement, and levels of hormone receptors ER and PgR.…”

Evaluation of the Quantitative Analytical Methods Real-Time PCR for HER-2 Gene Quantification and ELISA of Serum HER-2 Protein and Comparison with Fluorescence in Situ Hybridization and Immunohistochemistry for Determining HER-2 Status in Breast Cancer Patients

“…Moreover, the tissue-based methods give information on the HER-2 status of the primary tumor, and it is assumed that this is indicative of metastatic potential. Measurement of circulating HER-2 ECD in serum (s-HER-2) has been shown to be useful for assessing the prognosis and for predicting the response to trastuzumab (11,12 ).…”

Clinical usefulness of human epidermal growth factor receptor-2 extracellular domain as a biomarker for monitoring cancer status and predicting the therapeutic efficacy in breast cancer

“…21,22 Since the measurement of serum HER2ECD levels is a simple, noninvasive and reproducible method, we assessed its availability as a biomarker for indicating the efficacy of anticancer treatment or for monitoring cancer status including progression or regression of cancer. According to a systemic review by Carney et al, 23,24 the positive rates of serum HER2ECD in primary and metastatic breast cancer were 18.5% (0-38) and 43% (23-80), respectively. These results are compatible with the positivity of other conventional tumor markers.…”