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Radiotherapy after surgery may be omitted in low-risk breast cancer
The addition of whole-breast irradiation to breast-conserving surgery conferred a modest but statistically significant reduction in risk for ipsilateral breast tumor recurrence among women aged 65 years or older, according to phase 3 study results.
However, researchers observed a low risk for ipsilateral breast tumor recurrence among all women in the study, regardless of whether they received whole-breast radiotherapy. That finding suggests radiotherapy may be safely avoided in some patients, researchers wrote.
Ian H. Kunkler
Ian H. Kunkler, MD, of the department of clinical oncology at Edinburgh Cancer Centre at Western General Hospital, and colleagues evaluated data from 1,326 women aged 65 years or older who had low-risk breast cancer (median age, 70 years; interquartile range [IQR], 67-74). All women underwent breast-conserving surgery and received adjuvant endocrine therapy.
Researchers assigned 658 women to also receive whole-breast irradiation. The other 668 women received no further treatment.
Median follow-up was 5 years (IQR, 3.84-6.05).
Ipsilateral breast tumor recurrence — the study’s primary endpoint — occurred in 1.3% (95% CI, 0.2-2.3) of women in the radiotherapy arm and 4.1% (95% CI, 2.4-5.7) of women in the control arm (P = .0002).
Women who did not receive radiotherapy were significantly more likely to experience ipsilateral breast tumor recurrence (HR = 5.19; 95% CI, 1.99-13.52). Radiotherapy also was associated with a 2.9% (95% CI, 1.1-4.8) absolute reduction in the risk for ipsilateral recurrence.
Women who received radiotherapy experienced and those who did not experienced similar rates of regional recurrence (0.5% vs. 1.5%), distance recurrence (0.5% vs. 1%), contralateral breast cancer (1.5% vs. 0.7%) and development of new cancers (3.7% vs. 4.3%).
Five-year OS was 93.9% (95% CI, 91.8-96) in both arms. Five-year breast cancer-free survival was 94.5% (95% CI, 92.5-96.5) in the control arm and 97.6% (95% CI, 96.2-99) in the radiotherapy arm.
“For women aged 65 years or older with early hormone receptor-positive, node-negative breast cancer (≤3 cm at the longest dimension) after breast-conserving surgery, adjuvant endocrine treatment alone is a reasonable therapeutic option for some women,” Kunkler and colleagues concluded. “We must stress that every patient should be assessed individually, with tumor characteristics, comorbidity and patients’ choice as determining factors, along with an assessment of benefits and risks of treatment.”
Reconsidering the use of radiotherapy after breast-conserving surgery in older women with low-risk disease may save considerable health care costs, Kevin S. Hughes, MD, of the Avon Comprehensive Breast Evaluation Center and Harvard Medical School, and Lauren A. Schnaper, MD, FACS, of the Greater Baltimore Medical Center Sandra and Malcolm Berman Comprehensive Breast Care Center, wrote in an invited commentary.
“It is time to face reality,” Hughes and Schnaper wrote. “We are no longer able to afford expensive treatments unless definite benefit is evident. In the new zero-sum world of health care, money spent on breast radiation for older women who do not really need it is money taken away from other aspects of their care. Many older women have more complex and life-threatening problems than their breast cancer. We should treat breast cancer in the most effective and least costly way possible and use the money saved to manage other major health-care issues.” – by Alexandra Todak
Disclosure: The researchers report no relevant financial disclosures.