The short answer
Oncotype DX looks at the activity of 21 genes in breast tumor tissue to help predict whether chemotherapy is likely to work. In TAILORx, about 70% of women with this type of breast cancer could avoid chemotherapy based on risk scoring.
Oncotype DX looks at the activity of 21 genes in tumor tissue to help predict whether chemotherapy is likely to work.
In TAILORx, five-year invasive disease-free survival was 92.8% with hormone therapy alone versus 93.1% with chemotherapy added, a difference NCI reports as not statistically significant.
About 70% of women with hormone receptor-positive, HER2-negative breast cancer could avoid chemotherapy based on risk scoring.
For women 50 or younger with scores of 16 to 25, there may be a small benefit from chemotherapy.
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This page is for people with early breast cancer who have an Oncotype DX result. It explains what the test measures, what the TAILORx trial found, and why the number alone decides nothing.
What the test measures
Oncotype DX is run on tumor tissue, not on a blood sample. NCI says it looks at the activity of 21 different genes to predict whether chemotherapy is likely to work for someone with breast cancer. It is not a scan. Ask your oncologist what your result means for you.
What TAILORx found
NCI reports that TAILORx enrolled 10,273 women at 1,182 sites in six countries. At five years, invasive disease-free survival was 92.8% with hormone therapy alone and 93.1% with hormone therapy plus chemotherapy. That difference was not statistically significant.
NCI says about 70% of women with hormone receptor-positive, HER2-negative breast cancer could avoid chemotherapy based on risk scoring.
There was one exception. For women 50 or younger with intermediate scores of 16 to 25, NCI says there may be a small benefit from chemotherapy. NCI advises these women to talk with their doctor.
Why the number alone decides nothing
Your oncologist reads the score alongside other facts about your cancer and your health. Trials have specific entry rules, and your situation may sit outside them. Writing down your questions before the visit can make that talk more useful.
If you have new symptoms or feel unwell while you wait, call your oncology team. Call 911 for an emergency.
Sources
Common questions
Does a high score mean my cancer has spread?
The test looks at gene activity in your tumor tissue. It is not a scan, so ask your oncologist what your result means for you.
What does Oncotype DX measure?
NCI says it looks at the activity of 21 different genes to predict whether chemotherapy is likely to work for someone with breast cancer.
My score is 18 and I am 46. What did TAILORx find for that?
NCI reports that for women 50 or younger with intermediate scores of 16 to 25, there may be a small benefit from chemotherapy. This is a specific discussion to have with your oncologist.
Questions to ask your doctor
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Written by: Cancer ExplainedSources last checked: 2026-07-30 what this meansLast updated: 2026-10-02Next planned review: 2027-07-30
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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