As reported in The Lancet Oncology by Meattini et al, interim analysis of the phase III EUROPA trial indicated that endocrine therapy was associated with poorer health-related quality of life (HRQOL) outcomes vs radiotherapy after breast-conserving surgery in women aged ≥ 70 years with luminal A–like low-risk early breast cancer.
Study Details
In the trial, 731 women from 17 sites in Italy and 1 site in Slovenia were randomly assigned between March 2021 and June 2024 to receive single-modality endocrine therapy (n = 366) or radiotherapy (n = 365). Endocrine therapy consisted of a daily oral aromatase inhibitor or tamoxifen, for a total planned duration of 5 to 10 years; radiotherapy was given as whole-breast or partial-breast irradiation at 26 to 40 Gy in 5 to 15 fractions.
The co-primary endpoints were change in HRQOL assessed by the global health status (GHS) scale of the EORTC QOL Questionnaire-30 at 24 months and 5-year ipsilateral breast tumor recurrence. The latter endpoint was not reported in the current interim analysis.
Key Findings
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. Of these patients, 86 in the radiotherapy group and 75 in the endocrine therapy group completed the 24-month HRQOL assessment. Among these patients, the mean baseline GHS score was 71.9 (standard deviation [SD] = 19.1) in the radiotherapy group and 75.5 (SD = 19.3) in the endocrine therapy group. At 24 months, the age-adjusted mean change from baseline in GHS was –3.40 (95% confidence interval [CI] = –7.82 to 1.03, P = .13) in the radiotherapy group and –9.79 (–14.45 to –5.13, P < .0001) in the endocrine therapy group; the adjusted mean difference favoring radiotherapy was 6.39 (95% CI = 0.14–12.65, P = .045).
Overall, treatment-related adverse events were reported in 67% of the radiotherapy group vs 85% of the endocrine therapy group. The most common grade 3 or 4 adverse events in the endocrine therapy group were arthralgia (7% vs 0% in radiotherapy group); pelvic organ prolapse (3% vs 0%); and fatigue, hot flashes, myalgia, bone pain, and fractures (2% vs 0% for each). Serious adverse events were reported in 15% vs 15% of patients. No treatment-related deaths were observed.
The investigators concluded: “Endocrine therapy was associated with a greater reduction in HRQOL, as measured by GHS, compared with radiotherapy at 24 months. 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.”
Icro Meattini, MD, of the Department of Experimental and Clinical Biomedical Sciences “M. Serio,” University of Florence, Italy, is the corresponding author of The Lancet Oncology article.
Disclosure: The study was funded by the Fondazione Radioterapia Oncologica. For full disclosures of the study authors, visit thelancet.com.
