The Who, What, Where, When and Sometimes, Why.

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 (ER-positive) breast cancers.

Tumor profiling

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 cancer.

Tumor profiling (using gene expression profiling tools) gives information about the genes in cancer cells. You may also hear the terms genomic testing and molecular profiling.

Oncotype DX is the most common tumor profiling test used in the U.S. Other tumor profiling tests, such as MammaPrint® and PAM50 (also called Prosigna®), are available. Oncotype DX is the only one used in breast cancer staging.

Oncotype DX testing

Oncotype DX tests a sample of the tumor (removed during a biopsy or surgery) for a group of 21 genes.

Benefit of chemotherapy for some ER-positive breast cancers

The results of the Oncotype DX test help predict the chance of metastasis (when cancer spreads to other organs) and the likelihood of benefit of getting chemotherapy in addition to hormone therapy.

Breast cancer staging

Oncotype DX can be included as part of breast cancer staging for some estrogen receptor-positive, lymph node-negative tumors [33]. 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.

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 [16,34-36]:

  • Tumor size smaller than 5 cm
  • ER-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 are 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, a more aggressive treatment plan that includes both hormone therapy and chemotherapy is usually recommended [34-36,118].

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 may be a small benefit of chemotherapy [39]. However, it’s unclear if this benefit is due to chemotherapy or the ovarian suppression caused by chemotherapy. So, these women may consider a treatment plan that includes [188]:

  • 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 less and lymph node-negative

For premenopausal women with lymph node-negative breast cancer, if the Oncotype DX score is less than 15, it’s unlikely chemotherapy would add much benefit to treatment. So, the use of hormone therapy alone is recommended [34-36,118].

In this way, Oncotype DX may help some women with ER-positive breast cancer avoid chemotherapy and its side effects.

Oncotype DX score is less than 26 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 less than 26, there may be a small benefit of chemotherapy [118]. However, it’s unclear if this benefit is due to chemotherapy or the ovarian suppression caused by chemotherapy. So, these women may consider a treatment plan that includes [188]:

  • 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 Oncotype DX score is 26 or higher, a more aggressive treatment plan that includes both hormone therapy and chemotherapy is usually recommended [34-36,118].

Oncotype DX score is less than 26

For postmenopausal women, if the Oncotype DX score is less than 26, the use of hormone therapy alone may be considered [34-36,118].

In this way, Oncotype DX may help some women with ER-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 for ductal carcinoma in situ (DCIS) test

Oncotype DX Breast DCIS Score® is a modified version of the Oncotype DX test for invasive breast cancer [40,119]. These two Oncotype DX tests are similar, but not exactly the same.

The Oncotype DX Breast DCIS test might help identify which cases of DCIS would benefit most from radiation therapy after lumpectomy, and which women might be treated with lumpectomy alone [40,120].

This test needs further study and isn’t part of standard care.

Updated 04/09/21

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