Oncotype

Oncotype is a brand of multigene expression assays developed by Genomic Health that are used to estimate cancer recurrence risk and to guide adjuvant therapy decisions. The best known test in the Oncotype family is Oncotype DX Breast Recurrence Score, a 21-gene assay used for certain early breast cancers to predict the likelihood of distant recurrence and the potential benefit of adding chemotherapy to endocrine therapy. The score is derived from quantitative measurement of gene expression in tumor tissue and is reported as a numeric result that is interpreted alongside clinical and pathologic factors.

In breast cancer, the Oncotype DX test is typically indicated for hormone receptor–positive, HER2-negative disease and has helped identify patients who may safely avoid chemotherapy when the predicted benefit is small. The test has influenced practice guidelines and standards of care, with results validated in multiple studies and incorporated into decision-making frameworks such as TAILORx, which refined chemotherapy recommendations for intermediate scores.

Beyond breast cancer, Oncotype DX has been developed for other tumor types. The Oncotype DX Colon Cancer Recurrence Score is a 12-gene assay intended to help predict the benefit of adjuvant chemotherapy for certain patients with stage II colon cancer. There is also an Oncotype DX DCIS Score, which assesses the risk of local recurrence after ductal carcinoma in situ and can inform treatment considerations.

The assays use RNA expression data obtained from formalin-fixed, paraffin-embedded tumor tissue and produce a score or category that is used in conjunction with traditional clinical and histopathologic factors. While influential in guiding therapy, the tests are not universal substitutes for standard clinical judgment and their applicability depends on cancer type, stage, and patient context.