The Oncotype® DX Breast Recurrence Score
Oncotype Dx® is a genomic laboratory test that helps guide treatment decisions for people with early-stage invasive breast cancers. Genomic tests look at the genes in tumors. This can tell us more about your risk of the cancer coming back. Genomic tests are not the same as genetic tests. Genetic tests look for a single-gene mutation in your body (like BRCA 1 and 2), whereas genomic tests look at the genes in the tumor.
Genomic tests are a way to look specifically at your tumor for information to help guide your treatment options. There are several genomic tests currently available. This article focuses on the Oncotype DX® breast recurrence score test. This test helps determine if having chemotherapy in addition to endocrine (hormone) therapy after surgery will lower your risk of the cancer coming back (recurring).
The Oncotype DX® test is endorsed by all major cancer research/treatment organizations, including the National Comprehensive Cancer Network (NCCN) and the American Society of Clinical Oncology (ASCO). It has been studied extensively and has proven to be a valuable tool in guiding treatment planning for individuals with certain types of breast cancer.
Who should get this test?
To better understand if this test is right for you, an understanding of normal breast tissue is helpful. Breast tissue is made up of lobules that produce milk, and ducts that carry the milk to the nipple. Breast cancer starts in a duct or a lobule. Where the cancer starts, along with how it looks under the microscope, determines the type of breast cancer you have (i.e. ductal cancer vs. lobular cancer). Oncotype DX® testing is used if you meet the following criteria:
- You are diagnosed with invasive breast cancer.
- The Oncotype® DX test is mainly used in women with breast cancer but is being studied in men with breast cancer.
- The stage of your cancer is I, II, or IIIA.
- Your lymph nodes can be positive or negative.
- The cancer is ER+(estrogen receptor-positive) and HER2 negative.
- This information is found on your pathology report and means that the cancer is likely to respond to hormone therapy.
How does the test work?
After you have surgery (lumpectomy or mastectomy), samples of the tumor are sent to Exact Sciences Laboratory where the test is performed. Results take about two weeks to be returned to your provider.
Scientists look at the tumor samples and determine the levels of expression of 21 specific genes in the tumor tissue. Sixteen of the genes are cancer-related; the other 5 are used as "reference" genes. Based on the level of expression of each of these genes, a score is assigned. This is called the Recurrence Score (RS). This score is on a scale of 0-100, with higher scores indicating a greater risk of recurrence. Your recurrence score is looked at in combination with your age and the size and grade of your tumor to determine the best course of treatment to prevent recurrence for you.
What does the recurrence score mean?
In individuals over the age of 50
- A score of 0-25 indicates a low risk of recurrence. The risks associated with chemotherapy would outweigh the benefits of having chemotherapy.
- A score of 26-100 indicates a high risk of recurrence. The benefits of chemotherapy in preventing a future recurrence outweigh the risks.
In individuals under the age of 50
- A score of 0-15 indicates a low risk of recurrence. Likely the risks associated with chemotherapy would outweigh the benefits of having chemotherapy.
- A score of 16-20 indicates a low to medium risk of recurrence. It is likely the benefit of chemotherapy will not outweigh the risks.
- A score of 21-25 indicates a medium risk of recurrence. The benefits of chemotherapy likely will outweigh the risks of side effects.
- A score of 26-100 indicates a high risk of recurrence. The benefits of chemotherapy are likely greater than the risks of side effects.
What does the research tell us?
The recommendations about treatment options come from the results of a number of studies. Most recently, the TailoRx study looked specifically at recurrence scores in women under 50. This study looked at over 10,000 women over 9 years. The study’s goal was to determine how well the Oncotype DX breast recurrence score predicted which patients would benefit from adding chemotherapy to their treatment plan. This study showed:
- Women with lymph node-negative breast cancer who have a score of 0-25 had outcomes that were excellent with endocrine (hormone) treatment alone (no chemotherapy).
- In women with a score from 25-100, chemotherapy treatment significantly reduced future recurrence.
Other studies have found:
- For women with lymph node-negative cancer and a recurrence score of less than 18, there was little or no benefit to chemotherapy.
- In those with intermediate scores (18-30), there was no substantial benefit to chemotherapy in preventing future recurrence.
- Women with higher recurrence scores had a large benefit from receiving chemotherapy.
- Studies of women with positive lymph nodes (the cancer has spread to 1-3 lymph nodes), found that chemotherapy should be considered with an RS of 18-100.
Is the test covered by my insurance?
The test costs about $4,000 and is covered by Medicare and many private insurance companies. Exact Sciences will assist patients and physicians' offices with insurance claims. They also offer financial assistance to those who qualify for financial need. The test could determine the need for 6 or more months of chemotherapy treatments and all the associated costs, making it beneficial for the patient and insurer.
Resources for More Information
Information and resources for patients and caregivers from Exact Sciences.
My Breast Cancer Treatment
Information and resources for patients and caregivers from Genomic Health/Exact Sciences
Burstein, H. J. (2020). Systemic Therapy for Estrogen Receptor-Positive, HER2-Negative Breast Cancer. New England Journal of Medicine, 383(26), 2557-2570.
Pease, A. M., Riba, L. A., Gruner, R. A., Tung, N. M., & James, T. A. (2019). Oncotype DX® recurrence score as a predictor of response to neoadjuvant chemotherapy. Annals of Surgical Oncology, 26(2), 366-371.
Sparano, J. A., Gray, R. J., Makower, D. F., Pritchard, K. I., Albain, K. S., Hayes, D. F., ... & Sledge Jr, G. W. (2018). Adjuvant chemotherapy guided by a 21-gene expression assay in breast cancer. New England Journal of Medicine, 379(2), 111-121.
Sparano, J. A., Gray, R. J., Ravdin, P. M., Makower, D. F., Pritchard, K. I., Albain, K. S., ... & Sledge Jr, G. W. (2019). Clinical and genomic risk to guide the use of adjuvant therapy for breast cancer. New England Journal of Medicine, 380(25), 2395-2405.
Williams, A. D., McGreevy, C. M., Tchou, J. C., & De La Cruz, L. M. (2020). Utility of Oncotype DX in male breast cancer patients and impact on chemotherapy administration: a comparative study with female patients. Annals of Surgical Oncology, 27, 3605-3611.