[Producing evidence for all: geriatric oncology and the challenge of equity in health care].

In France, nearly one third of breast cancers occur after the age of 70, yet these patients have long been underrepresented in the clinical trials that inform treatment decisions. This exclusion, rarely made explicit, became embedded in clinical practice. The ASTER 70s trial, published in The Lancet in 2025, provides new evidence. It shows that adjuvant chemotherapy does not improve overall survival in women aged 70 and older, while exposing them to significant toxicity and potential loss of autonomy. This seemingly negative result constitutes a decisive finding: it demonstrates that it is both possible and necessary to generate evidence for populations long excluded from clinical research. It calls for a rethinking of health equity.