An analysis of the EUSOMA database, covering 9,660 patients from 72 European breast units, confirms that in women aged 65 or over with low-risk, luminal A-like tumours treated with conserving surgery, adjuvant therapy improves oncological outcomes, and that combining radiotherapy with endocrine therapy offers the greatest protection.
What was known
In low-risk early breast cancer and in older patients the intensity of adjuvant therapy is debated: advanced age, comorbidities and a favourable biological profile lead some guidelines to consider de-escalating radiotherapy or endocrine therapy. Broad data comparing the options in real-world clinical practice were lacking.
What this work adds
This is an analysis of the EUSOMA database, which collected data from patients treated in EUSOMA-certified breast units between 2010 and 2022. Local, nodal and distant recurrences, breast cancer specific survival (BCSS) and overall mortality were analysed with univariable and multivariable methods. The options compared were adjuvant endocrine therapy (ET) alone, whole breast irradiation (WBI) alone, ET+WBI, or no adjuvant therapy.
Main results
A total of 9,660 patients from 72 breast units in 14 European countries were included. Tumours were pT1 in 85.8% of cases, all were luminal A-like and all patients had negative nodes. The ET+WBI combination was given to 8,154 patients (84.4%); ET alone to 806 (8.3%); WBI alone to 386 (4.0%); and no adjuvant therapy to 314 (3.3%). Median follow-up was 1.87 years. Compared with no adjuvant therapy, multivariable analysis showed that ET+WBI significantly improved in-breast tumour recurrence-free survival (IBTRFS) (HR 0.28; 95% CI 0.10-0.79; p=0.016) and breast cancer specific survival (HR 0.12; 95% CI 0.03-0.51; p=0.004). ET alone (HR 0.57), WBI alone (HR 0.51) and both treatments combined (HR 0.26) were also associated with a lower risk of in-breast recurrence.
What it means
The authors conclude that, despite the short follow-up, adjuvant treatments had a positive impact on outcomes in this large series of low-risk patients who had undergone conserving surgery. The finding does not by itself settle who can safely de-escalate treatment, but it does provide real-world clinical evidence — more than 9,000 patients across 72 units — for shared decision-making.
A view from the breast unit
The work comes from the EUSOMA database, which brings together breast units certified for quality, volume and multidisciplinary care. It reinforces the value of systematic registration and comparison between centres, and underlines the importance of documenting and auditing treatment decisions in older patients.
Reference: Aristei C, Tomatis M, Ponti A, Marotti L, Battisti NML, Leung Cheung K, et al. Impact of whole breast irradiation, endocrine therapy or their combination on outcomes of early-stage, luminal A-like, low-risk, breast cancer patients aged 65 years or over: Insights from the EUSOMA database. European Journal of Cancer, 2026. https://doi.org/10.1016/j.ejca.2026.116259
