Low Recurrence Seen With Omission of Radiation in Some Breast Cancer Cases

THURSDAY, Aug. 17, 2023 (HealthDay News) -- The incidence of local recurrence at five years is low among women aged at least 55 years with T1N0, grade 1 or 2, luminal A breast cancer who were treated with breast-conserving surgery and endocrine therapy without radiotherapy, according to a study published in the Aug. 17 issue of the New England Journal of Medicine.

Timothy J. Whelan, B.M., B.Ch., from McMaster University in Hamilton, Ontario, Canada, and colleagues performed a prospective cohort study involving women aged at least 55 years who had undergone breast-conserving surgery for T1N0, grade 1 or 2, luminal A-subtype breast cancer and had received adjuvant endocrine therapy. Ki67 immunohistochemical analysis was performed, and patients with a Ki67 index of 13.25 percent or less did not receive radiotherapy.

Five hundred eligible patients were enrolled. The researchers found that recurrence was reported in 2.3 percent of the patients at five years after enrollment. In 1.9 percent of the patients, breast cancer occurred in the contralateral breast, and recurrence of any type occurred in 2.7 percent.

"Women 55 years of age or older with T1N0, grade 1 or 2, luminal A breast cancer had a very low risk of local recurrence at five years after breast-conserving surgery when treated with endocrine therapy alone," the authors write. "The prospective and controlled nature of this study supports our conclusion that such patients are candidates for omission of radiotherapy."

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