OncotypeDx helps select women who will benefit from chemotherapy.  It identifies women with hormone-responsive breast cancer who have very good outcomes with hormonal therapy, who do not need chemotherapy.  Using gene expression profiling, it analyzes a sample of the tumour (removed during a biopsy or surgery) for a group of 21 cancer-related genes that predict the behaviour of cancer, it’s potential to recur, and responsiveness to hormonal treatment.

Oncotype Dx can also be used to determine the risk of recurrence in DCIS (ductal carcinoma in situ) as well as the likelihood of the benefit of radiation therapy after DCIS surgery.