Some older women with breast cancer could safely avoid radiotherapy without harming their chances of survival. These study results were presented at the 2014 San Antonio Breast Cancer Symposium, and published in Lancet Oncology (2015; doi:10.1016/S1470-2045(14)71221-5).
Older women with early breast cancer who undergo breast-conserving surgery and hormone therapy gain very modest benefit from radiotherapy, according to the researchers.
The findings suggest that a carefully defined group of patients who are at low risk of recurrence could avoid the health risks and side effects associated with radiotherapy, such as fatigue and cardiac damage.
Currently, older women with early hormone-sensitive breast cancer are offered surgery to remove their tumor, followed by hormone treatment and radiotherapy. Few trials have assessed the benefits of radiotherapy in older women who underwent breast-conserving surgery.
Scientists at the University of Edinburgh in Scotland led an international, randomized, controlled trial (PRIME 2) that included 1,326 patients ages 65 years and older with early stage, hormone-receptor positive breast cancers. Their tumors were surgically removed and had not spread to the axillary lymph nodes.
Half of the women received radiation as well as hormone treatment and half received hormone treatment alone.
After 5 years, roughly 96% of both groups had survived, and most deaths were not caused by breast cancer. Approximately 1% of those who received radiotherapy had their cancer recur in the treated breast vs 4% of those who did not receive radiotherapy.
“While radiotherapy will remain the standard of care for most women after breast-conserving surgery, the absolute reduction in risk of recurrence from radiotherapy in low-risk older women receiving hormone treatment is very modest. This makes omission of radiotherapy an option for selected older patients,” said Professor Ian Kunkler, MD, of the University of Edinburgh’s Cancer Research Centre.