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The following is a summary of “Single-modality endocrine therapy versus radiotherapy after breast-conserving surgery in women aged 70 years and older with luminal A-like early breast cancer (EUROPA): a preplanned interim analysis of a phase 3, non-inferiority, randomised trial,” published in the December 2024 issue of Oncology by Meattini et al.    

The optimal post-surgical therapy for older women with low-risk, early-stage breast cancer remains uncertain, particularly regarding the effects of radiotherapy versus endocrine therapy on HRQOL and ipsilateral breast tumor recurrence (IBTR).  

Researchers conducted a prospective study to compare the effects of radiotherapy and endocrine therapy on HRQOL and IBTR in older women with luminal A-like early breast cancer.  

They conducted a phase 3, non-inferiority, randomized trial (1:1) at 18 hospitals across, involving women aged 70 years or older with stage I, luminal A-like breast cancer. Participants received either endocrine therapy or radiotherapy. Endocrine therapy included aromatase inhibitors or tamoxifen, while radiotherapy was delivered as whole or partial breast irradiation (5–15 fractions). The co-primary endpoints were HRQOL, assessed by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire 30-item core module (EORTC QLQ-C30), and IBTR.  

The results showed that 731 women were randomly assigned to receive radiotherapy (n=365) or endocrine therapy (n=366), with 104 patients in the radiotherapy group and 103 in the endocrine therapy group. After a median follow-up of 23.9 months, the adjusted mean change in Global Health Status (GHS) was –3.40 in the radiotherapy group and –9.79 in the endocrine therapy group (P<0.0001), favoring radiotherapy with an adjusted mean difference of 6.39 (P=0.045), AEs were less frequent in the radiotherapy group (67%) than in the endocrine therapy group (85%). Common grade 3–4 events included arthralgia, pelvic organ prolapse, fatigue, and hot flashes, with higher rates in the endocrine therapy group. Serious AEs occurred in 15% of patients in both groups, with no treatment-related deaths in either.  

They concluded that radiotherapy might better preserve HRQOL compared to endocrine therapy in older women with low-risk, early breast cancer.  

Source: thelancet.com/journals/lanonc/article/PIIS1470-2045(24)00661-2/abstract