933 – Impact of metabolic syndrome on survival outcomes in breast cancer: real-world evidence from a tertiary cohort

Abstract

Introduction: Metabolic syndrome (MetS) has been increasingly recognized as a potential modifier of cancer outcomes.
However, its impact on survival in breast cancer patients remains uncertain, particularly in real-world populations and
across different molecular subtypes.
Objective: To evaluate the association between MetS and survival outcomes in breast cancer patients using real-world data.
Methods: This retrospective cohort study included 1,962 women with histologically confirmed invasive breast cancer
treated with curative intent between 2014 and 2024 at a tertiary public center. MetS was defined according to established
international criteria. Overall survival (OS) and breast cancer-specific survival (BCSS) were estimated using the Kaplan–
Meier method and compared using the log-rank test. Multivariable Cox proportional hazards models were applied to
adjust for age, clinical stage, molecular subtype, and treatment modalities.
Results: MetS was identified in 486 patients (24.8%). Patients with MetS were older and had significantly higher body
mass index and prevalence of cardiometabolic comorbidities, including hypertension, dyslipidemia, and glucose intolerance (all p<0.001). After a median follow-up of 96 months, MetS was associated with significantly worse survival outcomes.
Mean OS was 112.4 months in the MetS group compared with 142.8 months in patients without MetS (log-rank p=0.012).
Similarly, BCSS was significantly reduced in the MetS group (115.1 vs. 145.3 months; log-rank p=0.018). In multivariable
analysis, MetS remained independently associated with worse OS (hazard ratio [HR] 1.42; 95% confidence interval [CI]
1.08–1.86; p=0.011) and BCSS (HR 1.38; 95%CI 1.01–1.88; p=0.042), without interaction with molecular subtype.
Conclusion: MetS is independently associated with worse survival outcomes in breast cancer in a real-world setting,
regardless of tumor molecular subtype. These findings support the integration of metabolic assessment into oncologic
risk stratification and management.
Ethics: The study was approved by the institutional ethics committee and registered in the Plataforma Brazil (CAAE
61004522.6.0000.5463).