Genomic Tests for Breast Cancer
Genomic tests, also called genomic assays, look closely at a sample of cancer tissue to see how active certain genes are. The activity level of the genes can help predict how likely the cancer is to grow and spread (metastasize). Genomic test results help doctors make decisions about whether having more treatments after surgery (like chemotherapy or radiation) would be beneficial.
Genomic tests also go by other names. For example, they may sometimes be called genomic assays or gene expression profiling tests. Genomic tests are one type of biomarker test.
Genomic testing versus genetic testing
Although their names sound similar, genomic tests and genetic tests are very different.
Genetic tests are used to find out about inherited mutations in a person’s genes. If someone has certain mutations, they may be at risk for specific types of cancer. But genetic testing is used for other things, too — a person may get genetic testing, for example, when they’re considering getting pregnant to see whether they could have a child with an inherited genetic condition.
Genomic testing looks at specific genes in a cancer tumor itself to see how active they are and whether they have any mutations. Genomic testing can help doctors predict how likely the cancer is to come back (recur) over time and whether certain treatments might reduce that risk. The results might lead an oncologist to recommend chemotherapy or radiation after surgery, for example. Or they may help the oncologist decide how many years of hormonal therapy to recommend.
What are the genomic tests for breast cancer?
There are currently seven genomic tests used to analyze early-stage (stage I, stage II, or stage IIIa) breast cancer or DCIS (ductal carcinoma in situ).
Used for: early-stage, hormone receptor-positive breast cancer that is either node-negative – meaning the cancer hasn’t spread to the lymph nodes – or that has spread to no more than three lymph nodes. It can be used if the cancer is HER2-positive or HER2-negative. The Breast Cancer Index test analyzes 11 genes to help predict the risk of breast cancer coming back five to 10 years after diagnosis. The test is done up to five years after a breast cancer diagnosis. After five years of hormonal therapy, the test helps people and their doctors decide if five more years of hormonal therapy (for a total of 10 years of hormonal therapy) would offer benefits.
Used for: DCIS. The DCISion RT test creates a score based on seven genes in DCIS, along with a person’s age, the size of the DCIS tumor, and the margins (the healthy rim of tissue around the DCIS when it’s removed). The resulting score estimates the 10-year risk of the DCIS coming back or developing into invasive breast cancer after lumpectomy alone or lumpectomy followed by radiation. Scores range from zero to 10. DCIS with a score of zero to three is considered to have a low risk of recurrence and a low risk of invasive disease. If the DCIS has a score higher than three, it’s considered to have an elevated risk of recurrence. Understanding the 10-year risk of cancer returning can help people and their doctors decide if radiation after lumpectomy would offer more benefits than risks.
Used for: early-stage, estrogen receptor-positive, HER2-negative breast cancer that is either node-negative (the cancer hasn’t spread to the lymph nodes) or that has spread to no more than three lymph nodes. The EndoPredict test analyzes 12 genes and then creates what’s called a molecular score. The molecular score is combined with some of the cancer’s other features – the size of the tumor and whether the cancer is node-negative or node-positive. The score helps predict the risk of the cancer coming back in a part of the body away from the breast (called distant metastasis or distant recurrence) within 10 years of diagnosis. People and their doctors use these results to help decide if chemotherapy or other treatments after surgery would be beneficial.
Used for: early-stage breast cancer that is either node-negative or has spread to no more than three lymph nodes and is no larger than 5 centimeters. The cancer can be hormone receptor-positive or -negative. Although the test can be used for both HER2-positive or HER2-negative cancers, it’s more commonly used for HER2-negative. The MammaPrint test analyzes 70 genes. The results categorize the breast cancer as having a high risk or low risk of coming back within 10 years of diagnosis. Understanding the size of this risk helps people and their doctors decide if chemotherapy or other treatments after surgery should be part of their treatment plan.
Used for: early-stage, hormone receptor-positive, HER2-negative breast cancer that is either node-negative or has spread to no more than three lymph nodes. The Oncotype DX Breast Recurrence Score test analyzes 21 genes. The Recurrence Score helps predict the risk of recurrence. And unlike the other genomic tests, it also specifically estimates how likely a person is to benefit from chemotherapy. People and their doctors use the results to decide if adding chemotherapy to hormonal therapy after surgery would offer benefits.
Used for: DCIS. The Oncotype DX Breast DCIS Score test analyzes 12 genes in DCIS to help predict the risk of DCIS recurrence or invasive breast cancer recurrence within 10 years of DCIS diagnosis. The results help people and their doctors decide if radiation therapy after DCIS surgery would offer benefits.
Genomic Test Helps Decide Which DCIS Needs Radiation
Dec 8, 2023Used for: early-stage, hormone receptor-positive, HER2-negative breast cancer in post-menopausal women who have had surgery to remove the cancer. The Prosigna Breast Cancer Prognostic Gene Signature Assay analyzes 50 genes to estimate the risk of distant metastasis within 10 years of diagnosis. The results are known as the Risk of Recurrence score. The Risk of Recurrence score is also based on several other characteristics of the cancer, including size, subtype, and node status. The Risk of Recurrence score helps post-menopausal women and their doctors decide on the best treatments after surgery.
Which genomic test is right for you?
If you’ve been diagnosed with DCIS, you and your doctor will decide if the Oncotype Breast DCIS Score of the DCISion RT test is right for your unique situation.
If you’ve been diagnosed with early-stage breast cancer, you and your doctor will work together to decide if any of the other tests can help you make treatment decisions.
What happens if you get a “borderline” score on a genomic test?
Sometimes the results of a genomic test such as OncotypeDX show a “borderline” recurrence risk score. This means that the potential benefits of chemo or other treatments after surgery aren’t as clear.
In this situation, your oncologist might try to gather more information to help make a decision. For example, they might suggest using a different genomic test (such as MammaPrint, if you already had an OncotypeDX test). The score from the second test could then serve as a kind of tiebreaker.
Keep in mind that your oncologist will consider a number of other factors — in addition to the results of genomic testing — when making a recommendation about whether or not you should get chemo, radiation therapy, or other treatments after surgery, such as your age, the size and grade of the cancer, any other health conditions you have, your family history of breast cancer, and your preferences.
“When we get a borderline score, we talk a lot with the patient about weighing the pros and cons of chemotherapy or other treatments for them as an individual — and we make a decision about it together,” says Sameer Gupta, MD, MPH, a medical oncologist at Bryn Mawr Hospital in Bryn Mawr, PA.
Paying for genomic testing
Medicare and many private insurance companies cover some or all of the cost of genomic tests. Medicaid coverage for genomic tests varies by state.
Several of the companies that make genomic tests have programs that help people navigate the billing and insurance process (including obtaining prior authorizations and appealing denied claims). Some also offer flexible payment options or financial assistance for people who meet eligibility requirements.
Also, the nonprofit Triage Cancer offers a guide to insurance coverage for biomarker testing, which explains how to appeal denials of coverage and access financial assistance. You can also see a list of the state laws that require insurance coverage for biomarker testing.
Genomic Assays: What Are the Different Kinds and How Do They Work?
Jul 28, 2023— Last updated on June 10, 2025 at 4:17 PM