Metabolic health at breast cancer diagnosis and two-year survival: a prospective cohort study in a public healthcare setting.

Abstract

Background: Metabolic syndrome is common among women with breast cancer and may adversely affect prognosis. However, prospective evidence on changes in metabolic health after breast cancer diagnosis and their association with survival remains limited, particularly in routine public healthcare settings. This study evaluated metabolic health during the first two years after diagnosis and examined the association between metabolic syndrome at diagnosis and overall survival in women with breast cancer.

Methods: This prospective cohort study was conducted in a Brazilian public healthcare service and included women aged ≥ 40 years with newly diagnosed stage I-III invasive breast carcinoma who were followed for two years. Clinical, anthropometric, and laboratory assessments were performed at baseline and at 6, 12, 18, and 24 months. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. Overall survival was defined as the time from breast cancer diagnosis to death from any cause or last follow-up. Survival according to metabolic syndrome status at diagnosis was evaluated using Kaplan-Meier analysis and Cox proportional hazards models.

Results: A total of 165 women were recruited, of whom 126 were included in the analysis and 111 completed the two-year assessment. Among participants with longitudinal data, significant reductions were observed in the prevalence of dysglycemia, elevated systolic blood pressure, and low HDL cholesterol. No significant changes were found in obesity, increased waist circumference, hypertriglyceridemia, or overall metabolic syndrome prevalence. During follow-up, 15 patients died. Women who died had a higher prevalence of metabolic syndrome at diagnosis than survivors (73% vs. 41%, p = 0.020) and higher baseline fasting glucose levels (p = 0.021). Metabolic syndrome at diagnosis was associated with lower overall survival (log-rank p = 0.021) and a higher risk of mortality (hazard ratio 9.09; 95% confidence interval 1.73-47.9), although this estimate should be interpreted as exploratory because of the limited number of events.

Conclusions: In this prospective cohort of women with breast cancer treated in a Brazilian public healthcare setting, metabolic syndrome was highly prevalent at diagnosis and was associated with poorer two-year overall survival in an exploratory analysis. Although favorable changes were observed in selected metabolic parameters during follow-up, obesity and the overall prevalence of metabolic syndrome remained largely unchanged. These findings support the incorporation of metabolic assessment and multidisciplinary cardiometabolic care into breast cancer management and survivorship programs and require confirmation in larger cohorts with longer follow-up.