A study from @NEJM suggests that chemotherapy is not always necessary for women with intermediate-risk, early-stage breast cancer. bit.ly/2MjqfPr via @MedStarWHC
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What the data say
Researchers in the study examined the results of more than 10,000 women with breast cancer who had a test called Oncotype DX. The test is performed on their tumor to estimate the risk of recurrence through measuring the activity of several cancer genes involved in cell growth and their response to hormone therapy (a cancer treatment that limits the growth of cancer causing hormones) and chemotherapy. Women were only included in the study that had estrogen receptor positive (ER+) tumors, tumors that were negative for human epidermal growth factor receptor (HER2) over expression, and had negative lymph nodes.
Approximately 17 percent of women who met criteria for this study had high-risk scores and were advised to undergo chemotherapy. Approximately 16 percent of women had low-risk scores and were recommended to only receive hormonal therapy.
The results focused on the remaining 67 percent of women who were considered at intermediate risk. All these women had breast cancer surgery and hormone therapy, and half also got chemotherapy. After nine years, 94 percent of the patients from both groups were still alive, and about 84 percent of the survivors had no signs of cancer, which suggests that chemotherapy made no difference in their types of cancer.
What’s next for chemotherapy?
Even before this study, breast cancer treatment standards had been moving away from chemotherapy for select patients. As more advanced and personalized treatment options have become available, chemotherapy recommendations are made less often. Moreover, I expect as more targeted therapies and immunotherapies are scientifically studied and become available, less chemotherapy (and associated toxicity) will be needed.
At MedStar Washington Hospital Center, we routinely use genomic tests such as Oncotype Dx to identify patients who are at low or intermediate risk of breast cancer recurrence and are not likely to benefit from chemotherapy. However, we know that women at high-risk of breast cancer recurrence who have breast cancer that is triple-negative, HER2-positive, or lymph-node positive can benefit from chemotherapy.
This research will help validate treatment decisions for more women and their doctors. The next step in research will be extended, longer-term follow-up of breast cancer patients. Taking it a step further, we may improve genomic assays to determine whether there is a better line in the sand at which we can feel 100 percent confident that a woman doesn’t need chemotherapy. I don’t know when we’ll ever get there, but I do think there will be improvements in the near future. In the short-term, I believe we’ll see women with breast cancer and their doctors feel more comfortable using genomic tests to make decisions about chemotherapy.
