The study, published Wednesday by the New England Journal of Medicine, looked at women 65 and older with early-stage breast cancer that may respond to hormone therapy. All the women had surgery and hormone therapy and were divided into a group that underwent radiation and a group that went without it. Ten years after surgery, survival rates were nearly equal in both groups, suggesting that more women could forgo radiation without affecting their survival.
The results support efforts by some doctors to reduce treatment for breast, blood and prostate cancers without reducing the odds of survival. Researchers are testing whether more limited chemotherapy can spare patients the harsh side effects and higher costs while maintaining the benefits of surgery or radiation treatment. Many doctors now recommend seeing people after symptoms of prostate cancer or some lymphomas are detected, rather than treating them right away.
Some are exploring whether young patients with breast-cancer tumors can skip radiation with few symptoms.
“For a long time, anyone who had invasive breast cancer was taking a gamble,” said Sarah Medek, MD, a radiation oncologist at the University of Cincinnati Cancer Center. Now, we’re trying to tease out who needs it and when.”
Radiation still has benefits, the doctors said. Cancer recurrence rates were higher among women who did not receive radiation in the new study. Some doctors said that for some people, with longer projected life expectancies or tumors that are less receptive to hormone therapy, radiation will be important.
“Avoiding local recurrence is a value for many women,” said Kurshan Gerber, MD, a radiation oncologist at NYU Langone’s Perlmutter Cancer Center, who was not part of the research. “Do they want to do everything they can?”
According to estimates by the National Cancer Institute, about 280,000 cases of breast cancer will be diagnosed in the US in 2022, making it the most common cancer in women. About a quarter of annual diagnoses occur in women ages 65 to 74. Most have tumors that make them candidates for hormone therapy.
Research has shown that cancer can be prevented with radiation and hormone therapy after surgery to remove part of the breast. Ian Kunkler, an oncologist at the University of Edinburgh, said because the trials often exclude older patients, there is less evidence that radiation benefits them to the same extent. and lead author on the new study.
The National Comprehensive Cancer Network in the US stated in 2004 that women age 70 and older with early-stage breast cancer who plan to take hormone therapy can skip radiation after surgery. Research suggests that guidance is not applied consistently.
In the new study, researchers enrolled nearly 1,300 breast cancer patients age 65 and older and followed nearly half of them for a decade. Among women who did not receive radiation in addition to hormone therapy after tumor removal, cancer came back in their breast in about 10%, compared with 1% among women who underwent radiation.
But the overall survival rate in both groups was almost equal at 81%. Of the 231 deaths recorded during the trial, 16 were related to breast cancer in women who did not receive radiation and 15 were related to breast cancer in women who did.
“It’s a really important recognition that’s going to make people say, ‘Hey, we’re going to be fine without radiation,'” said Harold Burstein, MD, a breast-cancer specialist at the Dana-Farber Cancer Institute in Boston who led the study. not included in “It’s going to allow physicians to drop more and more women.”
Radiation treatment regimens have become shorter and less intense in recent years, the oncologist said. But they still produce side effects including swelling, fatigue and skin irritation. There are also rare but serious effects on the heart and lungs and a low risk of developing secondary cancers. Treatment can be expensive and requires repeated clinical visits over weeks.
“If I could skip radiation without harming my outcome, I would have,” said Elizabeth Shaughnessy, MD, breast surgeon and director of cancer survivorship at the University of Cincinnati Cancer Center. She said she had a tumor in her breast, making her ineligible to undergo radiation.
Doctors said some women still choose radiation if it can reduce the risk that the cancer may come back and require another surgery or more drugs. Oncologists said some people with long-term survival, including healthy women, should consider radiation because the risk of recurrence increases with time.
“Is the toxicity concern for radiation more of a concern or cause for concern than breast cancer coming back?” Wendy Woodward, interim chair for the department of breast radiation oncology at the University of Texas MD Anderson Cancer Center. “It may affect what you choose.”
Claire Grace, 72, a retired teacher in Houston, was diagnosed with breast cancer in May 2022 and decided to have surgery at MD Anderson, rather than have her entire breast removed. Now on hormone therapy, she said she chose to undergo radiation for peace of mind.
“I thought it was a good insurance policy,” Ms. Grace said.
That said, she joined a clinical trial testing the long-term effects of radiation called proton therapy because of the treatment.