Oncotype DX
Oncotype DX® is a tumor profiling test. It helps determine the benefit of using chemotherapy in addition to hormone therapy to treat some estrogen receptor-positive, HER2-negative early breast cancers.
Tumor profiling
Tumor profiling tests give information about the genes in cancer cells (genes in the tumor cells, not in the normal (non-cancer) cells in a person’s body).
Tumor profiling tests look at patterns of expression for a set of genes in a sample of the tumor removed during a biopsy or surgery.
Tumor profiling may also be called genomic testing, molecular profiling or genetic signature testing.
Oncotype DX is the most common tumor profiling test used in the U.S. and the only one used in breast cancer staging.
Other tumor profiling tests, such as MammaPrint®, are available.
Oncotype DX testing
Oncotype DX tests a sample of the tumor (removed during a biopsy or surgery) for a group of 21 genes. These genes are in the tumor cells, not in the normal (non-cancer) cells in a person’s body.
Breast cancer staging
Oncotype DX results can be included as part of breast cancer staging for some estrogen receptor-positive, HER2-negative, lymph node-negative tumors [167]. It’s the only tumor profiling test used in breast cancer staging today.
If Oncotype DX testing is done, the results are used in combination with other factors to determine stage.
Learn more about breast cancer staging.
Benefit of chemotherapy for some estrogen receptor-positive breast cancers
The results of the Oncotype DX test help predict the:
- Chance of metastasis (when cancer spreads to other organs)
- Possible benefit of chemotherapy in addition to hormone therapy
When can Oncotype DX be used?
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 [10,320]:
- Tumor size smaller than 5 cm
- Estrogen receptor-positive (and will be treated with hormone therapy)
- HER2-negative
- Lymph node-negative or 1-3 positive lymph nodes
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.
Oncotype DX scores may be interpreted differently for women before and after menopause.
Oncotype DX scores for premenopausal women
Oncotype DX score is 26 or higher
For premenopausal women with either lymph node-negative or lymph node-positive breast cancer, if the Oncotype DX score is 26 or higher, then a more aggressive treatment plan that includes both hormone therapy and chemotherapy is usually recommended [10,85,320-321].
Oncotype DX score is 16-25 and lymph node-negative
For premenopausal women with lymph node-negative breast cancer, if the Oncotype DX score is 16-25, there’s a small benefit of chemotherapy in addition to hormone therapy [322]. However, it’s unclear if this benefit is due to chemotherapy or the ovarian suppression caused by chemotherapy [10]. So, these women may consider a treatment plan that includes [10]:
- Chemotherapy and hormone therapy (with tamoxifen, or with an aromatase inhibitor plus ovarian suppression)
- Ovarian suppression and hormone therapy (with tamoxifen or an aromatase inhibitor)
Oncotype DX score is 15 or lower and lymph node-negative
For premenopausal women with lymph node-negative breast cancer, if the Oncotype DX score is 15 or lower, it’s unlikely chemotherapy would add much benefit to treatment. So, the use of hormone therapy alone is recommended [10,320].
In this way, Oncotype DX may help some women with estrogen receptor-positive breast cancer avoid chemotherapy and its side effects.
Oncotype DX score is 25 or lower and 1-3 positive lymph nodes
For premenopausal women who have breast cancer with 1-3 positive lymph nodes, if the Oncotype DX score is 25 or lower, there may be a small benefit of adding chemotherapy [10,321]. However, it’s unclear if this benefit is due to chemotherapy or the ovarian suppression caused by chemotherapy [10]. So, these women may consider a treatment plan that includes [10]:
- Chemotherapy and hormone therapy (with tamoxifen, or with an aromatase inhibitor plus ovarian suppression)
- Ovarian suppression and hormone therapy (with tamoxifen or an aromatase inhibitor)
Oncotype DX scores for postmenopausal women
Oncotype DX score is 26 or higher
For postmenopausal women, if the Oncotype DX score is 26 or higher, then a more aggressive treatment plan that includes both hormone therapy and chemotherapy is usually recommended [10,85,320-321].
Oncotype DX score is 25 or lower
For postmenopausal women, if the Oncotype DX score is 25 or lower, chemotherapy may not be needed, and the use of hormone therapy alone is standard care [10,320-321].
In this way, Oncotype DX may help some people with estrogen receptor-positive breast cancer avoid chemotherapy and its side effects.
Learn about Susan G. Komen®’s funding of the TAILORx study and how Oncotype DX is helping many women avoid chemotherapy.
Under study
Oncotype test for ductal carcinoma in situ (DCIS)
Oncotype DX Breast DCIS Score® is under study. It’s a modified version of the Oncotype DX test for invasive breast cancer [324-325]. These two Oncotype DX tests are similar but are not exactly the same.
The Oncotype DX Breast DCIS Score might help identify which cases of DCIS would benefit most from radiation therapy after lumpectomy, and which women might be treated with lumpectomy alone [325-327].
This test needs further study and isn’t part of the standard of care.
Updated 04/11/24
