1055 – OCTABRAZIL – breast cancer in octogenarian women: a real-world study at a brazilian tertiary hospital

Abstract

Introduction: Breast cancer in women ≥80 years presents challenges due to comorbidities, functional status and underrepresentation in trials. This study evaluated clinical characteristics, treatment patterns, and survival in this population.
Methods: A retrospective cohort of patients (≥80 years) diagnosed between 2008–2021 at a Brazilian tertiary hospital.
Survival was analyzed using Cox proportional hazards regression.
Results: Among 390 patients, 293 (75.1%) had no treatment-related complications, while 97 (24.9%) developed adverse
events. Comorbidity burden was high: hypertension (78%), polypharmacy (34.6%), diabetes (30.7%), dementia (18%), and
heart failure (15.3%). Mean age was 85.7 years in patients without complications and 84.2 years in those with complications. Invasive ductal carcinoma (72.9%) and luminal-like subtype (77.9%) predominated. Staging was I (20%), II (25.1%),
III (26.4%), and IV (25.1%). Treatments included neoadjuvant (10.8%), primary surgery (39.2%), and palliative intent (50%),
mainly due to metastatic disease (49.7%), poor performance status (34.4%), or patient preference (15.4%). Complications
occurred in 16.6% of surgical cases, 50% with chemotherapy, 13.6% with endocrine therapy, and 27.2% with anti-HER2
therapy. Complications occurred at a higher rately in ECOG 0–2 patients (83.7%), likely reflecting treatment selection bias.
Treatment-related complications were not associated with overall survival (HR 1.17; 95%CI 0.87–1.60). Five 30-day deaths
occurred. In multivariable analysis excluding stage IV and in situ disease, stage III (HR 1.61; 95%CI 1.11–2.34; p=0.012) and
palliative treatment due to poor performance status (HR 2.14; 95%CI 1.30–3.44; p<0.001) were independently associated
with worse survival rates. KPS 30–50% was associated with worse outcomes, without reaching statistical significance
(HR 1.83; 95%CI 0.92–3.63; p=0.084). After adjustment for KPS, ECOG lost statistical significance.
Conclusion: Functional status is a critical prognostic determinant. KPS may capture prognostic information more accurately than ECOG in octogenarians. Advanced stage and performance-driven palliative care predicted poorer survival.
Individualized strategies integrating functional status and tumor stage are essential to optimize therapeutic decisions.
Ethics: Research Ethics Committee Approval (CAAE 94921925.2.0000.0068).