A new study published in The Lancet raises questions about the standard post-surgical treatment for many older women diagnosed with a common form of breast cancer. The research suggests that chemotherapy may not significantly improve survival rates for women aged 70 and over with hormone receptor-positive, HER2-negative breast cancer. These findings contribute to a growing movement toward personalized cancer care, emphasizing the need to weigh treatment benefits against potential harms, particularly for an increasingly aging patient population.
For women aged 70 and older newly diagnosed with a common type of breast cancer, chemotherapy after surgery may not offer a significant survival benefit, a new study suggests. The research, published in August 2025 in The Lancet, adds to the growing conversation about tailoring cancer treatment to individual patient needs and minimizing unnecessary interventions, particularly in older adults.
The study focused on women with hormone receptor-positive (ER+), HER2-negative breast cancer – a type that responds to hormone therapy – and assessed whether adding chemotherapy to standard hormone therapy improved overall survival rates. While hormone therapy remains a cornerstone of treatment for this group, the role of chemotherapy has been debated.
Researchers at the Institut Curie conducted a randomized, phase III clinical trial, dubbed ASTER 70s, involving 1,089 patients aged 70 and over (with a median age of 75.1 years) across 84 centers in France and Belgium. All participants had undergone surgery for primary or recurrent localized breast cancer.
Approximately 40% of the study cohort (n=437) were identified as having geriatric frailty. Patients were randomly assigned in a 1:1 ratio to receive either four cycles of taxane- or anthracycline-based chemotherapy followed by hormone therapy (n=541), or hormone therapy alone (n=548).
After a median follow-up of 7.8 years, the results showed no statistically significant difference in overall survival between the two groups. At four years, survival rates were 90.5% in the chemotherapy group compared to 89.3% in the hormone therapy-only group. At eight years, rates were 72.7% and 68.3%, respectively, again showing no significant difference.
The study also highlighted the increased toxicity associated with chemotherapy. Grade 3 or higher adverse events were observed in 34% of patients who received chemotherapy, compared to just 9% in the hormone therapy-only group. Patients undergoing chemotherapy also reported a significant decline in their quality of life, experiencing fatigue, low white blood cell counts, anemia, fever, digestive issues, and reduced independence.
“These results suggest that a de-escalation strategy may be appropriate for these older patients,” the authors concluded, recommending that chemotherapy be reserved for specific cases where it is most likely to provide a benefit. The findings underscore the importance of carefully considering the risks and benefits of treatment, especially in an aging population.
