(HealthDay News) — Biomarkers can be used to guide decisions on systemic therapy for women with metastatic breast cancer, according to the American Society of Clinical Oncology Clinical Practice Guideline published online July 20 in the Journal of Clinical Oncology.

Catherine Van Poznak, MD, from the University of Michigan Comprehensive Cancer Center in Ann Arbor, and colleagues conducted a literature review of 17 articles relating to appropriate use of breast tumor biomarker assay results to guide decisions on systemic therapy for metastatic breast cancer. Eleven studies reported discordance between primary tumors and metastases in terms of hormone receptor or human epidermal growth factor receptor 2 (HER2) expression.

The researchers note that biopsy for confirmation of disease process and retesting of estrogen receptor, progesterone receptor, and HER2 status should be offered in patients with accessible metastases. Evidence is lacking for the impact on clinical outcomes of changing anticancer treatment based on receptor change. If supported by the clinical scenario and patient goals for care, the panel consensus was to use preferentially the estrogen receptor, progesterone receptor, and HER2 status of the metastasis to direct therapy. To contribute to decisions regarding therapy, carcinoembryonic antigen, cancer antigen 15-3, and cancer antigen 27-29 may be used as adjunctive assessments, but not alone.

“One of the most important conclusions from this guideline is the compelling need for further research on this topic,” the authors write.

Several authors disclosed financial ties to the pharmaceutical and biotechnology industries.

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