Oncotype DX® is a tumor profiling test that helps determine the benefit of using chemotherapy in addition to hormone therapy to treat some estrogen receptor-positive (ER-positive) breast cancers.
Every cell in your body has genes that contain the blueprints (genetic code) for your body. Similarly, every cell in a breast tumor has genes. These genes contain the blueprints for the tumor.
Tumor profiling (using gene expression profiling tools) gives information about the genes in cancer cells.
Oncotype DX is the most commonly used tumor profiling test in the U.S. and the only one used in breast cancer staging. Other tumor profiling tests (such as MammaPrint® and PAM50 (also called Prosigna®)) are available.
Oncotype DX tests a sample of the tumor (removed during a biopsy or surgery) for a group of 21 genes.
The results of the Oncotype DX test help predict the chance of metastasis (when cancer spreads to other organs) and the likelihood of benefit from chemotherapy in addition to hormone therapy.
Oncotype DX is part of breast cancer staging for some estrogen receptor-positive, lymph node-negative tumors. It’s the only tumor profiling test used in breast cancer staging today.
Sometimes, the Oncotype DX score can lower the breast cancer stage from IB, IIA, IIB or IIIA to stage IA .
Learn more about breast cancer staging.
Oncotype DX helps predict the chance of metastasis and the likelihood of benefit from chemotherapy for early breast cancers that are all of the following [16,43-45]:
Oncotype DX may also be used for some postmenopausal women with invasive breast cancers that are ER-positive, HER2-negative and lymph node-positive when chemotherapy is being considered [43-44].
If Oncotype DX testing is right for you, your oncologist will review your test results with you and discuss how the Oncotype DX score may guide your treatment plan.
If Oncotype DX shows a person has a fairly high risk of metastasis (the Oncotype DX score is high), a more aggressive treatment plan that includes both hormone therapy and chemotherapy may be advised [16,43-45].
If the test shows a low risk of metastasis (the Oncotype DX score is low), the use of hormone therapy alone may be considered [16,43-45]. In this way, Oncotype DX may help some people with ER-positive breast cancer avoid chemotherapy and its side effects.
For women 50 and younger with an Oncotype DX score of 16-25, the TAILORx study showed there may be a benefit of including both hormone therapy and chemotherapy in the treatment plan .
Findings from the TAILORx study show, for some women over 50 with an Oncotype DX score showing an intermediate risk of metastasis, treatment with hormone therapy alone may be as effective as treatment with hormone therapy and chemotherapy .
However, whether or not people with an Oncotype DX score of 26-30 can avoid chemotherapy is still under study.
Learn about Susan G. Komen®’s funding of the TAILORx study and how Oncotype DX is helping many women avoid chemotherapy.
The Oncotype DX test for invasive breast cancer has been modified to help predict the chance ductal carcinoma in situ (DCIS) will return as DCIS or invasive breast cancer .
It tests a sample of the DCIS tumor (removed during a biopsy or surgery) for a group of 12 genes.
This test may help identify which cases of DCIS would benefit most from radiation therapy after lumpectomy (and which women might be treated with lumpectomy alone) .
This test needs further study and is not yet part of standard care.
TAILORx Study Cites Chemotherapy Not Needed For Some Breast Cancer Patients
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