The Oncotype DX test is a genomic test that analyzes the activity of a group of genes that can affect how a cancer is likely to behave and respond to treatment. The Oncotype DX is used in two ways:
to help doctors figure out a woman’s risk of early-stage, estrogen-receptor-positive breast cancer coming back (recurrence), as well as how likely she is to benefit from chemotherapy after breast cancer surgery
to help doctors figure out a woman’s risk of DCIS (ductal carcinoma in situ) coming back (recurrence) and/or the risk of a new invasive cancer developing in the same breast, as well as how likely she is to benefit from radiation therapy after DCIS surgery
The results of the Oncotype DX test, combined with other features of the cancer, can help you make a more informed decision about whether or not to have chemotherapy to treat early-stage hormone-receptor-positive breast cancer or radiation therapy to treat DCIS.
Who is eligible for the Oncotype DX test?
You may be a candidate for the Oncotype DX test if:
you’ve recently been diagnosed with stage I or II invasive breast cancer
the cancer is estrogen-receptor-positive
there is no cancer in your lymph nodes (lymph node-negative breast cancer)
you and your doctor are making decisions about chemotherapy.
Most early-stage (stage I or II), estrogen-receptor-positive breast cancers that haven’t spread to the lymph nodes are considered to be at low risk for recurrence. After surgery, hormonal therapies such as an aromatase inhibitor or tamoxifen are prescribed to reduce the risk that the cancer will come back in the future. Whether or not chemotherapy is also necessary has been an area of uncertainty for patients and their doctors.
If you’ve been diagnosed with early-stage, estrogen-receptor-positive breast cancer, the Oncotype DX test can help you and your doctor make a more informed decision about whether or not you need chemotherapy. (Some research also suggests the test may help postmenopausal women with estrogen-receptor-positive breast cancer that has spread to the lymph nodes make chemotherapy decisions. Talk to your doctor if you are in this group.)
You also may be a candidate for the Oncotype DX test if:
you’ve recently been diagnosed with DCIS
you’re having lumpectomy to remove the DCIS
DCIS is the most common form of non-invasive breast cancer. DCIS usually is treated by surgically removing the cancer (lumpectomy in most cases). After surgery, hormonal therapy may be recommended if the DCIS is hormone-receptor-positive. Radiation therapy may be recommended for some women. Doctors aren’t always sure which women will benefit from radiation therapy.
If you’ve been diagnosed with DCIS, the Oncotype DX test can help you and your doctor make a more informed decision about whether or not you need radiation therapy.