Investigating Time-Varying Predictor Effects on Cardiovascular Outcomes in Breast Cancer Survivors.

Area of Science:

• Oncology
• Cardiology
• Epidemiology

Background:

• Cardiovascular disease (CVD) is a significant concern for breast cancer (BC) survivors.
• Prognostic factors for CVD can change over time and differ based on the type of CVD.
• Understanding these dynamics is crucial for effective patient management.

Purpose of the Study:

• To examine the time to first occurrence of six CVDs in BC patients.
• To investigate the influence of molecular subtype on CVD risk, adjusting for age, tumor stage, and radiation therapy.
• To analyze time-dependent associations between BC molecular subtypes and CVD incidence.

Main Methods:

• Utilized data from 36,605 women diagnosed with BC in the Norwegian Cancer Registry.
• Employed Cox regression analyses with death as a competing risk for six CVDs.
• Applied random survival forest (RSF) analysis to capture non-linear and time-varying relationships.

Main Results:

• The association between molecular subtype and time to first CVD varied across different CVD types.
• Heart failure (HF) risk showed a non-linear relationship with molecular subtype.
• Molecular subtype was the second most important predictor for time to first HF, after age.

Conclusions:

• Time to heart failure is dependent on breast cancer molecular subtype in a time-dependent manner.
• Random survival forest analysis effectively identifies complex predictor-survival relationships.
• These findings underscore the importance of considering molecular subtype in CVD risk assessment for BC patients.