• Posted November 6, 2025

Many Breast Cancer Patients Can Safely Skip Radiation After Mastectomy, Study Finds

A new study suggests that many women with early-stage breast cancer may not need radiation after a mastectomy, thanks to advances in modern cancer treatment.

The international clinical trial followed more than 1,600 women who had early-stage breast cancer. They were considered at intermediate risk for recurrence, meaning they had Stage 2 cancer with up to three affected lymph nodes, or tumors with aggressive features and no lymph node involvement.

All of the women had surgery to remove the breast and lymph nodes. They also received advanced anti-cancer drugs.

Half were randomly assigned to receive radiation after surgery, and half were not.

Nearly a decade later, survival rates were almost identical in both groups: 81.4% for women who had radiation versus 81.9% for those who did not.

“We’ve now shown that with contemporary anti-cancer treatments, the risk of recurrence is very, very low — sufficiently low to avoid radiotherapy in most patients,” study lead Ian Kunkler, a professor of oncology at the University of Edinburgh, told The New York Times.

The findings were published Nov. 5 in The New England Journal of Medicine.

Radiation did slightly reduce the chance of cancer returning in the chest wall, but the number of recurrences was small: 29 women total.

The treatment did not affect whether cancer spread elsewhere in the body or whether cancer returned for the women.

Doctors say the results help clarify treatment for women at intermediate risk.

“It was clear for low-risk cancer that you did not need radiation after mastectomy and that for high-risk patient you did need radiation and still do it after mastectomy,” Dr. Harold Burstein of Dana-Farber Cancer Institute, who was not involved in the study, told The Times.

Further, radiation is already being used less often in lower-risk cases, partly because it can cause short-and long-term side effects.

These may include skin irritation, swelling, lung inflammation and higher risk of lymphedema, a condition that causes painful arm swelling.

It can also make breast reconstruction more difficult, The Times reported.

Experts warn that radiation is still important for women with higher-risk disease who continue to benefit from the treatment.

More information

The Mayo Clinic has more on radiation therapy for breast cancer.

SOURCE: The New York Times, Nov. 5, 2025