According to an interim analysis of the EUROPA trial, older patients with stage I luminal-like breast cancer who underwent endocrine therapy had a significant reduction to health-related quality of life over 24 months when compared to those patients who received radiation therapy.

These results will be presented by Icro Meattini, MD, Florence University Hospital, Florence, Italy, at the 2024 San Antonio Breast Cancer Symposium.

The phase 3 EUROPA trial randomized patients with luminal-like breast cancer. after breast conserving surgery to receive either exclusive endocrine therapy (n = 366) or exclusive radiation therapy (n = 365). The coprimary end points of the study were the 2-year health-related quality of life, as determined by global health status (GHS) scale of the European Organization for Research and Treatment of Cancer QLQ-C30, and 5-year ipsilateral breast tumor recurrence. Secondary end points include locoregional recurrence, contralateral breast cancer, distant metastases, breast cancer specific survival and overall survival rates, adverse events, and individual scale scores from QLQ-C30, QLQ-BR45, QLQ-ELD14 EORTC modules up to 5 years post-treatment. 

At the time of the current interim analysis, the radiation therapy arm included 104 patients, and the endocrine therapy arm included 103 patients. Patients in the radiation therapy arm had a mean GHS score at baseline of 71.9 compared to a mean GHS score at baseline of 75.5 in the endocrine therapy arm. The radiation therapy arm had a mean GHS change of –1.1 at 24 months, compared to a mean change of –10.0 in the endocrine therapy arm. Significant factors that contributed to the change in GHS score were treatment type (P = .045) and baseline GHS value. The adjusted mean differences between the radiation therapy and endocrine therapy arms at 24 months showed a significant difference that favored radiation therapy (P = .0453). 

At the time of the interim analysis, there were no ipsilateral breast tumor recurrence, locoregional recurrence, or distant metastasis events reported in either arm. Contralateral breast cancer events occurred in 2 patients in the radiation therapy arm and 1 patient in the endocrine therapy arm. There were 4 deaths in the radiation therapy arm and 2 in the endocrine therapy arm, though none were due to breast cancer-related causes.

Study authors concluded “these findings will help shared decision-making while awaiting final study results.”

Source:

Meattini I. Exclusive endocrine therapy or radiation therapy in women aged 70+ years with luminal-like early breast cancer (EUROPA): Preplanned interim analysis of a randomized phase 3 trial. Presented at 2024 San Antonio Breast Cancer Sympsosium. Dec 10-13, 2024; San Antonio, TX. Abstract: SESS-3480