Chemotherapy May Not Be Necessary for Certain Breast Cancers, Study Finds

According to new research presented at the 2020 San Antonio Breast Cancer Symposium, many postmenopausal women with breast cancer derive no additional benefit from chemotherapy. They can achieve the same outcomes and survival rates with hormone-blocking medications alone.

The Rx for Positive Node, Endocrine Responsive Breast Cancer (RxPONDER) trial, funded by the National Cancer Institute, looked at 5,000 women across nine countries with hormone receptor(HR)-positive, HER2-negative breast cancer that had spread to between one and three lymph nodes.

All of the women studied had an Oncotype DX score of 25 or less. The Oncotype DX explores breast, colon, and prostate cancers’ unique biology, predicting cancer recurrence, and guiding treatment decisions. Based on Oncotype DX tissue test findings, the Oncotype DX Breast Recurrence Score predicts the likelihood of recurrence for breast cancer patients. A score of 25 or less, on a scale of 1 to 100, indicates a low-to-intermediate risk of breast cancer recurrence.

“The Oncotype test is like having a molecular microscope," Steve Shak, MD, chief medical officer for Exact Sciences, the parent company of Oncotype DX, tells Verywell. "It allows us to see the underlying biologies that make one tumor different from another and determine the right treatment. The goal of Genomic Health and Exact Sciences was to identify better not only who is more or less likely to have a recurrence, but also to identify better who might benefit from chemo and who has no benefit.”

The trial concluded that there may still be some chemotherapy benefit in premenopausal women who meet these criteria. However, for their postmenopausal counterparts, chemotherapy did not significantly decrease recurrence or improve survival rates.

“The RxPONDER clinical trial was one of the largest trials ever to determine the effect of chemo, if any, in women with this type of cancer,” Shak says. “Twenty years ago, we were giving toxicities to everyone to benefit a few. But almost 80% of women with node-negative breast cancer do not need chemo. This study also identified the important minority for whom chemo is still potentially lifesaving.”

Improving Patient Quality of Life

For patients who can avoid chemotherapy, the impact on their quality of life is tremendous.

“This year, more than 270,000 women in the United States will be diagnosed with breast cancer, and approximately two-thirds of them have this HR-positive, HER2-negative subtype," Shak says. "This is the most common and most treatable, but we’ve got to treat it right."

The RxPONDER trial shows the benefits of tailoring breast cancer treatment to each individual. "It identified that more than 75% of women received chemo for node-positive breast cancer because it appeared there might be a benefit for everyone," Shak says. "The results now show that the majority of women with one to three positive lymph nodes can be safely spared chemo without compromising their outcomes."

Having more detailed information on a patient’s cancer type also guides patients and providers in making more patient-specific treatment plans.

“Almost every breast cancer is different at the gene level, so there is no one-size-fits-all approach,” Julie Gralow, MD, clinical director of breast medical oncology at Seattle Cancer Care Alliance and incoming chief medical officer for the American Society of Clinical Oncology (ASCO), tells Verywell.

When Gralow is making a recommendation for treatment, she looks in-depth at the patient and factors in:

• The type of cancer they have
• Any comorbidities they may have
• Where the patient is in life

"We need to take into account the features of the treatment as well, and the side effects," she says. "One sort of chemo might not be good if you had pre-existing heart disease or neuropathy.”

Advocating for Your Breast Cancer Care

For newly-diagnosed breast cancer patients and their support systems, speaking with oncologists and evaluating treatment options can be daunting. But Gralow says there are many things patients and caregivers can do to feel more confident working with their care teams.

“Patients and their family members feel that they overnight need to become experts on breast cancer,” Gralow says, adding this is not the case. “Establish a relationship with a healthcare team that you can trust. They should explain your diagnosis, the features of it, and make their recommendation with the support for why they chose one plan over the other.”

To facilitate better communication between cancer care providers and patients, Gralow recommends a support person attend appointments and take notes so the patient can “listen, process, and think of the next question.” If you cannot have a support person present, Gralow suggests asking permission to record the visit.

“Studies show that patients retain little of what we tell them at the first visit, but having your visit recorded so you can listen again or you can share with family members can be helpful,” she says.

Gralow also cautions to be careful when doing online research.

“There is so much on the internet. Much of it is excellent, but so much of it is just wrong,” she says. Gralow recommends seeking out ASCO and the American Cancer Society websites for reliable information.

"The recent advancements in breast cancer allow many more women to choose the best treatment for them with an excellent chance of survival and the least amount of toxicity and side effects,” Shak says. “They will get smarter cancer care, and that’s what we all want.”