986 – Age-related differences in treatment and outcomes among women with breast cancer: a real-world cohort study

Abstract

Background: As the breast cancer population ages, understanding how age influences treatment decisions and survival
in real-world settings becomes increasingly relevant. Age-related differences in clinicopathological features, treatment
patterns, and outcomes were evaluated among women with surgically treated invasive breast cancer at a Brazilian public high-complexity referral center.
Methods: This retrospective cohort study included women aged 50 years or older with invasive breast cancer treated
surgically between 2020 and 2024. Patients were stratified into three age groups: 51–69 years, 70–74 years, and ≥75 years.
Clinicopathological variables, treatment patterns, recurrence, overall survival (OS), and disease-free survival (DFS)
were compared across groups using standard statistical methods. The study was approved by Plataforma Brazil (CAAE
87347725.8.0000.5463).
Results: A total of 2,148 patients were analyzed: 1,335 aged 51–69 years, 405 aged 70–74 years, and 408 aged ≥75 years.
Treatment intensity declined progressively with age. Rates of neoadjuvant chemotherapy were 28.3%, 20.7%, and 10.3%,
respectively; adjuvant chemotherapy, 28.3%, 22.2%, and 6.6%; and radiotherapy, 85.8%, 63.0%, and 36.0% (all p<0.001). In contrast, the oldest group showed the worst outcomes, with higher locoregional recurrence (2.2%, 3.0%, and 8.1%; p=0.001),
overall recurrence (2.2%, 3.0%, and 7.4%; p=0.004), and death rates (4.0%, 2.2%, and 10.3%; p=0.005). OS and DFS were significantly poorer with advancing age (OS, p=0.002; DFS, p<0.001). In multivariable analysis, triple-negative subtype, mastectomy, and axillary dissection were associated with higher mortality, while radiotherapy showed a protective effect.
Conclusions: Women aged 75 years or older had more unfavorable outcomes and received less intensive treatment, suggesting that advanced age remains strongly associated with poorer real-world breast cancer outcomes. These findings
highlight the need for more individualized, evidence-based treatment strategies to avoid undertreatment in older patients.
Ethics: Research Ethics Committee Approval (CAAE 87347725.8.0000.5463).