Australian Study Investigates Who May Safely Omit Postoperative Radiotherapy for Early Breast Cancer

By: Jenna Carter, PhD
Posted: Wednesday, March 13, 2024

Standard treatment for patients with early breast cancer often involves the use of adjuvant radiotherapy, which can have substantial short-term and longer-term morbidity and costs. An article published in The Lancet highlighted whether the combination of MRI and pathology findings could identify women with truly localized breast cancer who may safely omit radiotherapy. Gregory Bruce Mann, MBBS, FRACS, of The Royal Women’s Hospital, Parkville, Victoria, Australia, and colleagues examined the ipsilateral invasive recurrence rate at 5-year follow-up. Women with non–triple-negative breast cancer who underwent breast-conserving surgery without radiotherapy had a 5-year ipsilateral invasive recurrence rate of 1%.

“Confirmatory trials are needed, and future trials of radiotherapy de-escalation should include enhanced breast imaging,” the study authors noted.

A total of 443 patients (aged 50 or older) with cT1 N0 non–triple-negative breast cancer were included in this study. Patients were separated into two groups: group 1 included those with unifocal cancer who had breast-conserving surgery and omitted radiotherapy; group 2 included those who were offered standard treatment with excision of MRI-detected additional cancers. All patients were advised to receive systemic therapy. The primary outcome was an ipsilateral invasive recurrence rate at 5 years in group 1, which occurred after the 100th patient reached the 5-year follow-up. Other study outcomes included quality-adjusted life-years and cost-effectiveness.

Overall findings revealed that of the 201 patients in group 1 who had breast-conserving surgery without radiotherapy, the ipsilateral invasive recurrence rate at 5 years was 1.0%. In group 2, nine patients underwent mastectomy (2% of the total cohort), and the 5-year the ipsilateral invasive recurrence rate was 1.7%. Findings also revealed an increase in quality-adjusted life-years by 0.019 (95% confidence interval [CI] = 0.008–0.029) and a savings of $1,286 (U.S.; 95% CI = $907–$2,642) per patient.

Disclosure: The study authors reported no conflicts of interest.

The Lancet