What is the Oncotype DX assay?
The Oncotype DX diagnostic assay predicts the likelihood of chemotherapy benefit for those patients and quantifies the likelihood of breast cancer recurrence in women with newly diagnosed, stage I or II, node-negative, estrogen receptor-positive breast cancer treated with tamoxifen. A recent study also indicated that the Oncotype DX assay may also be prognostic and predictive of added chemotherapy (CAF) benefit for postmenopausal women with node-positive, hormone-receptor-positive breast cancer treated with tamoxifen. The test analyzes the expression of a panel of 21 genes.
The Oncotype DX assay is a validated genomic test that predicts the likelihood of breast cancer recurrence, the likelihood of patient survival within 10 years of diagnosis and the likelihood of chemotherapy benefit in early-stage, node-negative, ER-positive breast cancer. The Oncotype DX assay uses a reverse-transcriptase (RT) polymerase chain reaction (PCR) process to quantify the expression of specific mRNA for 16 cancer genes and 5 reference genes in paraffin samples obtained from a breast cancer biopsy, combining the expression results into a single score called the Recurrence Score® result.
