More women with breast cancer could skip harsh radiation, study says

More older women with low-risk breast cancer could forgo radiation after surgery to avoid further side effects and costs, research showed,as some doctors work to limit tough treatments without hurting survival.

Women in the study published Wednesday by the New England Journal of Medicine were 65 and older with early stage breast cancers that could respond to hormone therapy. The women all 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 in the two groups were almost equal, suggesting more women could skip 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, surgery or radiation can spare patients harsh side effects and high costs while maintaining the benefit of treatment. Many doctors now advise watching people after testing has found signs of prostate cancer or certain lymphomas rather than treating immediately.

Some are exploring whether younger patientswith breast-cancer tumors with certain traits could skip radiation, too.

“For a long time, anyone who had invasive breast cancer was getting the gambit,” said Sara Medek, a radiation oncologist at the University of Cincinnati Cancer Center, who wasn’t involved with the study. “Now, we’re trying to tease out who needs what and when.”

Radiation still has benefits, doctors said. Women who didn’t receive radiation in the new study had the cancer recur at higher rates. For some, including women with longer estimated life expectancies or tumors that are less receptive to hormone therapy, radiation will be important, some doctors said.

“Avoiding a local recurrence is a value for many women,” said Naamit Kurshan Gerber, a radiation oncologist at NYU Langone’s Perlmutter Cancer Center, who wasn’t a part of the research. “Do they want to do everything they can?”

Some 280,000 breast cancer cases in the U.S. were diagnosed in 2022, according to estimates from the National Cancer Institute, making it the most common cancer in women. About a quarter of annual diagnoses are among women 65 to 74. Most have tumors that make them candidates for hormone therapy.

Radiationand hormone therapy after surgery to removepart of the breast can keep cancer in check, research has shown.Because trials often exclude older patients, there is less evidence radiation benefits them to the same degree, said Ian Kunkler, an oncologist at the University of Edinburgh and lead author on the new study.

The National Comprehensive Cancer Network in the U.S. saidin 2004 that women 70 and older with early stage breast cancer who plan to get hormone therapy could skip radiation after surgery. Research suggests the guidance isn’t implemented consistently.

In the new study, researchers enrolled some 1,300 breast cancer patients 65 and older and followed about half of them for as long as a decade. Among women who didn’t get radiation in addition to hormone therapy after having tumors removed, about 10% had cancer return in their breast comparedwith 1% among the women who also underwent radiation.

But overall survival rates in both groups were almost equal at about 81%. Of the 231 deaths recorded during the trial, 16 were related to breast cancer among women who didn’t receive radiation and 15 were related to breast cancer among those who did.

“This is a really important validation that’s going to make people say, ‘Hey, we’re going to be OK without radiation,’” said Harold Burstein, a breast-cancer specialist at the Dana-Farber Cancer Institute in Boston, who wasn’t involved in the study. “It’s going to allow clinicians to spare more and more women.”

Radiation treatment regimens have become shorter and less intense in recent years, oncologists said. But they still generate 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 a secondary cancer. The treatment can be expensive and require repeated clinical visits over weeks.

“If I could have skipped out on radiation without a detriment to my outcome, I would have,” said Elizabeth Shaughnessy, a breast surgeon and director of cancer survivorship at the University of Cincinnati Cancer Center. Dr. Shaughnessy was diagnosed in 2019 with multiple tumors in her breast, making her ineligible to skip radiation, she said.

Some women still choose radiation if it can reduce the risk that cancer might come back and require another surgery or more drugs, doctors said. Some, including healthier women likely to live longer, should consider radiation because the risk of recurrence goes up with time, oncologists said.

“Is the anxiety of toxicity to radiation going to cause more anxiety or worry than the breast cancer coming back?” said Wendy Woodward, interim chair for the department of Breast Radiation Oncology at The University of Texas MD Anderson Cancer Center. “That might influence what choice you make.”

Klair Grace, 72, a retired teacher in Houston, was diagnosed with breast cancer in May 2022 and decided to have surgery at MD Anderson to remove part of her breast rather than all of it. Now on hormone therapy, she said she chose to undergo radiation for peace of mind.

“It felt like a good insurance policy,” Ms. Grace said.

She joined a clinical trial testing the long-term effect of a radiation called proton therapy, she said, because the treat