For women 65 and older with breast cancer, the odds of survival are nearly identical whether or not surgery is followed by radiation, according to a study published February 16 in the New England Journal of Medicine — which suggests it may be possible for this group to forgo taxing radiation treatment.
For individuals with early breast cancer, “historical trials showed that radiotherapy reduced the risk of recurrence within the breast after breast conserving surgery … by three- to fourfold,” says the lead study author, Ian Kunkler, MB BChir, an honorary professor of clinical oncology at the University of Edinburgh in Scotland.
But most of these previous trials included only younger women, leaving it unclear whether radiation would also benefit older adults with similar tumors, Dr. Kunkler says. Now the results of this new study suggest that radiation — which comes with burdensome side effects like breast pain, fatigue, and heart risks — may not always be needed for older women.
Survival Rates Were Nearly the Same With or Without Radiation
All 1,326 women in the study had small hormone-receptor positive (HR+) tumors. They all received breast-conserving surgery followed by hormone therapy (also called endocrine therapy) designed to prevent cancer from coming back. Half of them were randomly assigned to receive radiation, while the other half skipped this intervention.
Ten-year overall survival rates were virtually the same in the two groups, at 80.7 percent among those who received radiation and 80.8 percent among women who skipped it.
This aligns with a push among oncologists to take a more nuanced approach to treating early breast cancer, says Kunkler. “At present there is a trend towards trying to de-escalate treatment for patients with early breast cancer and move away from a 'one size fits all' approach,” he says. “Research is focused on identifying subgroups of patients based on clinical, pathological, and molecular features of breast cancer who may derive little or no benefit from postoperative radiotherapy.”
Radiation Does Prevent Breast Cancer Tumors From Reoccurring
While the survival rate was similar with and without radiation, this intervention did appear to prevent tumors from returning.
Without radiation, 9.5 percent of women had cancer return in the same breast within 10 years, compared with fewer than 1 percent of people who received radiation.
One in eight women in the United States will develop breast cancer at some point in their lives, according to the American Cancer Society; half of them will be at least 62 years old when they are diagnosed.
Some previous research has looked at the potential for endocrine therapy to reduce the risk of cancer recurrence in individuals who skip radiation. One five-year study of 500 women age 55 and older, presented at the 2022 meeting of the American Society of Clinical Oncology, found radiation didn’t impact the odds that cancer would return in the same breast where it was first diagnosed.
“The addition of radiation does not impact survival in older women with low-risk breast cancer, as long as endocrine therapy is taken,” says Alice Y. Ho, MD, the codirector of the breast clinical research unit at Duke University Medical Center in Durham, North Carolina.
“However, radiation does significantly reduce the risk of local recurrence,” says Dr. Ho, who wasn’t involved in the new study or the 2022 research. “Therefore, the decision really should be individualized to the patient, and physicians should help patients navigate this decision-making process.”