This study, called "ROSUBREAST", is a multicenter, double-blind, randomized clinical trial evaluating whether rosuvastatin (20 mg daily) can protect the heart in women with breast cancer receiving anthracycline-based chemotherapy. A total of 400 participants will be randomly assigned to receive either rosuvastatin or placebo for 12 months. The main goal is to determine whether rosuvastatin can prevent cancer treatment-related cardiac dysfunction (CTRCD), defined as a significant drop in heart pumping function. The study will also assess changes in cardiac strain, blood biomarkers, symptoms of heart failure, quality of life, and possible side effects.

Introduction: Anthracycline-induced cardiotoxicity significantly threatens the long-term cardiac health of breast cancer patients undergoing chemotherapy. Statins have shown potential cardioprotective effects without compromising cancer treatment efficacy. The ROSUBREAST study aims to evaluate the efficacy of rosuvastatin in preventing CTRCD in breast cancer patients receiving anthracycline-based chemotherapy. Methods: This multicenter, two-arm, double-blinded, superiority, parallel-group, randomized, placebo controlled clinical trial will be conducted across seven oncocardiology centers in Iran. A total of 400 participants will be enrolled and will be randomly assigned in a 1:1 ratio to receive either rosuvastatin (20 mg daily) or no intervention for 12 months. The primary endpoint is the incidence of CTRCD, defined as a ≥10% reduction in left ventricular ejection fraction (LVEF) to below the lower normal limit (53%). Secondary endpoints include changes in Global Longitudinal Strain (GLS), biomarkers (Troponin, NT-proBNP, hsCRP), and development of heart failure (HF). Ancillary endpoints are quality-of-life assessments and adverse effects of treatment. Conclusion: The ROSUBREAST study seeks to provide evidence on the cardioprotective role of rosuvastatin in breast cancer patients undergoing anthracycline-based chemotherapy, potentially informing clinical guidelines and improving patient outcomes.

Inclusion Criteria:

• Female individuals with ≥18 years of age
• Documented breast cancer diagnosis based on imaging and pathology findings
• Scheduled to receive the first time anthracycline-based chemotherapy

Exclusion Criteria:

• Baseline LVEF < 50%
• Prior Statin use or Statin use is indicated based on guidelines
• history of congestive heart failure (CHF) or cardiomyopathy
• Pregnancy or breastfeeding
• Unable to provide informed consent
• Unexplained persistent elevation of transaminases (>3 times upper limits of normal)
• Concomitant use of oral cyclosporine
• Metastatic invasion of cancer to other organs
• Previous cycles of chemotherapy
• Any contraindication for statin use

Female

The IPD used in the main analyses of CSR will be shared upon reasonable request from the principal investigator and confirmation by trial management committee (TMC).

The IPD can be shared after the release of CSR.

Reseaonable request for IPD sharing from the principal investigator will be assessed in TMC. If the commiittee agreed and confirmed the IPD sharing, the IPD will be shared through a suitable platform.