Interim results from the phase III EUROPA trial indicate that radiotherapy may better preserve health-related quality of life (HRQOL) compared to endocrine therapy in older women with luminal A-like early breast cancer. The study, presented at the 2024 San Antonio Breast Cancer Symposium and published in The Lancet Oncology, highlights the impact of treatment choice on the well-being of older patients undergoing breast-conserving surgery.
The EUROPA trial, conducted across 17 sites in Italy and 1 site in Slovenia, randomized 731 women aged 70 years and older between March 2021 and June 2024. Participants received either single-modality endocrine therapy (aromatase inhibitors or tamoxifen) or radiotherapy (whole-breast or partial-breast irradiation). The co-primary endpoints were the change in HRQOL at 24 months, assessed via the global health status (GHS) scale of the EORTC QOL Questionnaire-30, and the 5-year ipsilateral breast tumor recurrence rate.
HRQOL Outcomes
The interim analysis included 104 patients in the radiotherapy group and 103 in the endocrine therapy group, with a median follow-up of 23.9 months. Baseline GHS scores were similar between the groups (71.9 for radiotherapy vs. 75.5 for endocrine therapy). However, at 24 months, the age-adjusted mean change from baseline in GHS was -3.40 in the radiotherapy group and -9.79 in the endocrine therapy group. The adjusted mean difference favoring radiotherapy was 6.39 (95% CI = 0.14–12.65, P = .045).
Adverse Events and Treatment Discontinuation
Treatment-related adverse events were reported in 67% of the radiotherapy group and 85% of the endocrine therapy group. Grade 3 or 4 adverse events more common in the endocrine therapy group included arthralgia (7% vs 0% in radiotherapy), pelvic organ prolapse (3% vs 0%), and fatigue, hot flashes, myalgia, bone pain, and fractures (2% vs 0% for each). Within 24 months, 22.5% of patients who received endocrine therapy switched to a different treatment, and 12.4% of patients discontinued endocrine therapy.
Clinical Implications
Icro Meattini, MD, of the University of Florence, the corresponding author of The Lancet Oncology article, noted that while these interim results suggest radiotherapy might better preserve HRQOL in older women with low-risk early breast cancer, further data on disease control outcomes and final patient accrual are needed to draw definitive conclusions. The investigators emphasized the need for multidisciplinary and patient-centered personalized care.
The findings suggest that while endocrine therapy is often considered a less invasive option, its side-effect profile might affect long-term adherence and HRQOL, especially in frail patients. Conversely, short-course radiotherapy could offer a less burdensome alternative, potentially combining similar efficacy with improved tolerability. Final results from the EUROPA trial, including long-term recurrence and survival data, will further clarify the roles of radiotherapy and endocrine therapy in this population.
