Pink October 2026: Advancing breast cancer research, together

Advancing breast cancer research

The BCG’s research spans early and metastatic breast cancer, treatment optimisation, molecular research, toxicity management and quality of life.

Among its ongoing studies is the EORTC-2129 TREAT ctDNA phase III trial, investigating whether elacestrant can reduce distant relapses in patients with ER-positive/HER2-negative breast cancer who experience a ctDNA relapse after starting endocrine treatment. Around 120 sites in total are participating from 12 countries. By September 2026, 1129 patients had entered serial ctDNA screening and 46 had been randomised.

The EORTC-1745 APPALACHES study continued follow-up of its 373 randomised patients, reaching data maturity for its primary endpoint. Results will be presented at SABCS in December. Five EORTC sites (from Belgium and Portugal) continue to participate in the extension of EORTC-1408 AURORA, a molecular screening programme for metastatic breast cancer, and so far have included 38 patients.

Other projects address important unmet needs, including the EORTC-2565 NEOLDER study, evaluating tailored neoadjuvant treatment for vulnerable women aged 70 and older with triple-negative or HER2-positive breast cancer. The study received French public funding to support its clinical research activities in France on 10 July 2026, followed by the Prix Ruban Rose 2026 for translational research on 28 July 2026. The study has also applied for European funding.

New evidence from 20 years of follow-up

This year the BCG contributed to two important publications from the EORTC-22922/10925 trial, examining the long-term effects of irradiation of the internal mammary and medial supraclavicular lymph nodes in stage I–III breast cancer.

The first publication, in CA: A Cancer Journal for Clinicians, reports the trial’s 20-year results. The analysis found that breast cancer mortality was significantly lower among patients who received internal mammary and medial supraclavicular irradiation. However, deaths from other causes than breast cancer increased after 15 years, resulting in no long-term overall survival benefit. The authors emphasise the importance of very long-term follow-up and continued efforts to minimise radiation exposure to organs at risk.

The second publication, a complementary unplanned subset analysis published in The Lancet Oncology, evaluated the 20-year outcomes among patients with node-negative breast cancer. The findings indicated that irradiation significantly reduced breast cancer-specific mortality compared with the control group, while overall survival remained comparable between the two treatment arms.

Watch the 20-year follow-up discussion with Prof. Philip Poortmans and Prof. Orit Kaidar-Person:

Putting patients at the heart of research

The impact of breast cancer research is ultimately measured in patient survival and quality of life.

For World Cancer Day 2026, EORTC shared the story of Betty, a breast cancer survivor who participated in the EORTC-10041 MINDACT study. The 70-gene signature MammaPrint showed that she had a low genomic risk of recurrence, despite being considered at high clinical risk, allowing her to avoid chemotherapy.

Betty’s experience illustrates how clinical research can change treatment decisions and help patients avoid unnecessary treatment and its associated side effects.

Together, advancing breast cancer care

From personalised treatment and molecular research to radiotherapy, treatment optimisation and quality of life, the EORTC Breast Cancer Group continues to address important questions across the breast cancer continuum.

This Pink October, EORTC celebrates the researchers, healthcare professionals and patients who contribute to this progress, highlighting the power of international collaboration to turn clinical cancer research into better-informed care.

Learn more about the EORTC Breast Cancer Group and its research here. Interested in becoming a BCG member? Apply here.