Many women tell me that the worst part of being diagnosed with breast cancer is hearing that you need chemotherapy. The disease itself is bad enough, but having to deal with the side effects of chemo—hair loss, nausea, fatigue and months of trips back and forth to the hospital—just intensify their fears. However, there is a relatively new test that can be performed at the time of biopsy and diagnosis that can provide valuable information in tailoring a woman’s treatment plan. In some cases, in fact, it can shift the recommendation away from the chemotherapy.
The Oncotype DX Breast Cancer test is a diagnostic tool created to help patients who have been diagnosed with early stage, estrogen positive, HER2 negative ( another marker) breast cancer. The test provides important details about a patient’s specific tumor(s) which enables doctors to determine the likelihood of cancer recurrence as well as the probability that chemo would be a necessary component of treatment.
How Does the Test Work?
Traditionally, doctors have used standard measurements of tumors (such as size and whether or not the cancer has spread to the lymph nodes) to estimate whether the cancer will return. The Oncotype DX test measures a group of 21 breast cancer genes to see how active they are, and results are reported as a number between 0 and 100–referred to as the Recurrence Score®. This score provides the following information:
- A lower score means that the cancer has a lower chance of recurring, and therefore that the patient will receive minimal benefit from adding chemotherapy to the treatment plan.
- A higher score means there is a higher probability that the cancer will recur, and that the patient will receive significant benefit from chemo.
Does the Test Actually Work?
A study recently published in the NEJM used data from over 10,000 women who had undergone the Oncotype DX test. The study looked at a group who had low Recurrence Scores (between 0 and 10) who did NOT undergo chemotherapy as part of their treatment (instead, they received only hormonal therapy). The study showed that after a period of 5 years, 99% of these women were free of breast cancer recurrence. Thus, the test demonstrated accuracy in identifying those women who would have possibly been over-treated—that is, given chemo when they didn’t need it.
A second study, published in June of this year, demonstrated that when the Oncotype DX test was performed, nearly 30% of patients had a change in their treatment regimen such that hormonal (endocrine) therapy was the primary component—rather than a combination of chemotherapy and endocrine therapy. To date, the Oncotype DX test has been ordered by over 10,000 doctors for over 230,000 patients.
Will My Insurance Cover the Test?
In many cases, yes. If your doctor has ordered this test, contact your insurance company to ensure that it is covered. If not, there is a program called the Genomic Access Program (GAP) which was created by the company who developed the test (Genomic Health, Inc.) which can help make the testing available to you.
As physicians we take an oath to “do no harm.” In cases where traditional diagnostic standards would have justified chemotherapy, we might have been over-treating the patient and possibly “doing harm.” With the advent of the Oncotype DX test, we have the information we need to confidently recommend hormonal therapy in certain cases and allow patients to bypass the unpleasant side effects that chemo causes. In doing what’s best for the patient, sometimes less is more.