Paris, August 1, 2025 – The ASTER 70S study, promoted by Unicancer and the Institut Curie, demonstrates that adding chemotherapy to hormone therapy does not provide a significant survival benefit in women aged 70 and more affected by Hormonosensible breast cancer at high genomic risk. These results, published in the journal The Lancet, constitute a major advance towards a more personalized management, adapted to the age and the fragility of the patients.
In elderly women with hormone-sensitive breast cancer, the question of the interest of adjuvant chemotherapy remains controversial. The ASTER 70S study (Gerico11), conducted with 1,089 patients aged 70 and over, is the first randomized phase III study to assess the impact of adjuvant chemotherapy in this high -risk population, defined by a genomic signature: Genomic Grade Index (GGI).
Unbeatured efficiency, confirmed toxicity
The study compared two groups of patients: one having received chemotherapy followed by hormone therapy, and the other having received hormone therapy alone.
After a 7.8 -year -old median follow -up, the results show that The addition of chemotherapy does not provide significant benefit in terms of global survival. At four years old, the survival rate was 90.5 % in the chemotherapy group, compared to 89.3 % in the group without chemotherapy. At eight years old, rates were 72.7 % and 68.3 % respectively. The difference from 4.5 points to eight years is not statistically significant.
In terms of tolerance, chemotherapy has proven to be much more toxic. Adverse effects of grade 3 or more occurred in 34 % of patients treated with chemotherapy, compared to only 9 % in the hormone therapy group alone. In addition, patients who have received chemotherapy reported a more marked deterioration in their quality of life, especially in connection with fatigue, pain, digestive disorders and a drop in autonomy.
“The ASTER 70S study is a turning point in the management of elderly women with breast cancer. For the first time, a phase III study shows that the addition of chemotherapy does not provide a statistically significant benefit of overall survival, even in patients at high genomic risk. These results confirm that therapeutic decisions must take into account not only tumor biology, but also age, fragility and expectations of patients. They encourage to revise the way in which standards established in younger subjects are then applied to older subjects without high level of evidence or with little safeguards. ASTER 70S opens the way to a more targeted, fairer oncology and more turned towards the patient ” declares Professor Etienne Brain, Medical oncologist at the Institut Curie, principal investigator of the ASTER 70S study.
Collaborative research at the service of precision medicine
The ASTER 70S study was designed and coordinated by Unicancer R&D, in partnership with the teams of the Institut Curie. She mobilized the Gerico and UCBG research groups specializing in oncogeriatrics and breast cancer, and was based on 84 investigating centers distributed in France and Belgium, public and private, testifying to a rigorous organization and exemplary collaboration.
“ASTER 70S is an emblematic study of the engine role of Unicancer in academic research in oncology. It shows that ambitious clinical trials, focused on the needs of patients, can answer questions that have remained unanswered for too long. This collective work will make it possible to reduce unnecessary treatments and to improve the quality of life of elderly patients, based on robust data and representative of real life ”declares the Pr Jean-Yves Blay, president of Unicancer.
“This study perfectly illustrates the commitment of the Curie Institute to promote personalized oncology. This work devoted to the oldest patients, often excluded from major studies, are at the heart of the priorities of the Ihu Institute of Women’s Cancers, carried by the Curie Institute and fully mobilized around access to innovation, the quality of life of patients and the establishment of very specific routes, especially for elderly women “specifies Professor Steven Le Gouill, Director of the hospital ensemble at the Institut Curie.
Towards a more individualized therapeutic approach
This study marks a decisive advance for the management of breast cancers in elderly women. It confirms the need to adapt the treatments to the biological characteristics of tumors, but also to age, fragility and preferences of patients. It invites you to rethink the development model of innovations improving the management standards, taking into account more particularly the relationship between profits and risks for the elderly.
Aster 70s’ results call to favor a reasoned therapeutic de -escalation strategy in these elderly patients, by reserving adjuvant chemotherapy for specific cases, which are trying to identify two essential research programs (funded by a PRTK and the CRA), conducted on the large collection of tumor and blood samples. These results also open the way to future research on better tolerated alternatives, such as adjuvant bisphosphonates, CDK4/6 inhibitors, or approaches incorporating the patient’s aging biomarkers.
Bibliography
Adjuvant chemotherapy and hormonotherapy versus adjuvant hormonotherapy alone for women aged 70 years and older with high-risk breast cancer based on the genomic grade index (ASTER 70s): a randomised phase 3 trial. Etienne Brain, Olivier Mir, Emmanuelle Bourbouloux, Olivier Rigal, Jean-Marc Ferrero, Sylvie Kirscher, Djelila Alauache, Véronique d’Hondt, Aude-Marie Savoye, Xavier Durando, Francois P Duhoux, Laurence Venat-Bouvet, Emmanuel Blot, Jean-Luc Canon, Florence Rollo-Trad, Hervé Bonnefoi, Telma Roque, Jérôme Lemonnier, Aurélien Latouche, Julie Henriques, Magali Lacroix-Triki, Dewi Vernerey, and Gerico & Ucbg/Unicancence. The LancetJuly 31, 2025. Doi: 10.1016/S0140-6736 (25) 00832-3
