Statin use is associated with a lower risk of all-cause death in patients with breast cancer treated with anthracycline containing regimens: a global federated health database analysis.

Anthracyclines are associated with enhanced oxidative stress responsible for adverse events in patients with breast cancer. However, no study has investigated the potential anti-inflammatory role of statins in counteracting anthracycline toxicity. In this retrospective study utilizing a federated health network (TriNetX), patients with breast cancer (ICD code C50) treated with anthracyclines were categorized into two groups: statin users (for at least 6 months); and statin non-users. The primary outcome was the 5-year risk of all-cause death. Secondary outcomes were the risk of myocardial infarction, stroke, atrial fibrillation, ventricular arrhythmias, heart failure, and pulmonary embolism. Cox-regression analyses were used to produce hazard ratios (HRs) and 95% confidence intervals (CI) following 1:1 propensity score matching (PSM). We identified 3,701 statin users (68.8 ± 10.4 years) and 37,185 statin non-users (59.6 ± 12.8 years). After PSM, the 5-year risk of all-cause death was significantly lower in statin users (HR 0.82, 95% CI 0.74-0.91) compared to statins non-users. Analyzing the risk for secondary outcomes, only the risk of stroke was significantly increased in statin users (HR 1.27, 95% CI 1.01-1.61), while no associations were found for the other cardiovascular events. The risk of all-cause death in statin users was the lowest during the first year after the anthracycline's initiation. No significant difference was found between lipophilic and hydrophilic statins. In patients with breast cancer treated with anthracyclines, statin use is associated with a reduced risk of all-cause death. Prospective studies are needed to investigate the potential beneficial effect of statin initiation in cancer patients without other indications.