Retrospective cohort study of beta-blockers use in patients with ductal carcinoma in situ and risk of invasive breast cancer

In preclinical models, beta-adrenergic signaling induces the upregulated expression of metastasis-associated genes and downregulation of genes facilitating anti-tumor immune responses. A retrospective cohort study in Sweden investigated the association of beta-blocker use in DCIS patients and the risk of invasive breast cancer. Among 2535 DCIS patients with a median follow-up of 8.7 years, the cumulative incidence of invasive breast cancer at five years was 1.8%. The cumulative exposure to beta-blocker was associated with reduced risk of invasive breast cancer in a dose-dependent manner, though the effect was not statistically significant. The authors conclude that these results suggest a protective effect of beta-blocker use against invasive breast cancer after primary DCIS diagnosis.