Pretreatment cardiometabolic risk in newly diagnosed breast cancer: a molecular subtype analysis

Breast cancer is the most common female malignancy globally. With improved survival, cardiovascular diseases have become a key morbidity source due to shared cardiometabolic risk factors (e.g., dyslipidemia). While cardiovascular risk varies by breast cancer molecular subtype, baseline pre-treatment cardiovascular comorbidities and lipid abnormalities remain undercharacterized. We aimed to describe their prevalence and subtype-specific patterns in newly diagnosed patients.

This single-center retrospective cohort study included 5,246 Chinese women with newly diagnosed breast cancer (2014-2024), with all data collected before anticancer therapy. Patients were stratified into five molecular subtypes. Baseline cardiovascular comorbidities, tumor features, and serum lipids were analyzed using chi-square tests, ANOVA, and multivariable logistic regression.

Age, cardiovascular comorbidities, electrocardiographic abnormalities and lipid profiles differed significantly across subtypes. Overall dyslipidemia prevalence was 54.1%, highest in Luminal A and lowest in Luminal B (HER2 negative). Intravascular tumor thrombus was independently associated with dyslipidemia in all subtypes, with the strongest association in triple-negative breast cancer. Lymph node metastasis correlated with dyslipidemia only in Luminal B subtypes, and several factors showed subtype-specific associations.

Dyslipidemia is common at baseline in treatment-naive breast cancer patients and varies by molecular subtype. Tumor-related features, particularly intravascular tumor thrombus, are consistently associated with dyslipidemia. Early lipid screening and cardiovascular risk assessment may optimize cardio-oncology care.