multigene assay
Laboratory tests that analyze expression of multiple genes in breast cancer tissue to predict prognosis and likelihood of chemotherapy benefit.
Full Definition
Multigene assays are genomic tests that simultaneously analyze the expression levels of multiple genes in breast cancer specimens to provide prognostic and predictive information. These tests help identify patients who are likely to benefit from adjuvant chemotherapy versus those who can be safely treated with endocrine therapy alone. Common examples include Oncotype DX, MammaPrint, EndoPredict, and Prosigna. Each assay uses different gene panels and algorithms to generate risk scores or classifications. Results are particularly valuable for hormone receptor-positive, HER2-negative breast cancers where treatment decisions may be uncertain based on traditional clinicopathological factors. The assays analyze tumor tissue from surgical specimens or large core biopsies and provide quantitative scores that correlate with recurrence risk and chemotherapy benefit.
Usage
Usage note: Distinguish from single-gene tests like BRCA testing; these assays analyze multiple genes simultaneously for prognostic purposes.
In Context
- "The multigene assay indicated intermediate risk, prompting shared decision-making about chemotherapy." — Clinical consultation note
- "Tissue was sent for multigene assay to guide adjuvant treatment recommendations." — Treatment planning documentation