Survival outcomes of beta-blocker usage in HER2-positive advanced breast cancer patients: a retrospective cohort study.

Use of beta-blockers for cancer therapy Summary: Background • Evidence from preclinical research suggests that beta-blockers (BBs) could serve as anticancer agents and immune boosters. • Beta-blockers could therefore be a potential therapy for cancers. • Trastuzumab is a drug that affects the overall survival (OS) and progression-free survival (PFS) of patients with HER2-positive breast cancer by binding to the extracellular domain of HER2. • This study investigates the effect of BBs on trastuzumab therapy in patients with advanced breast cancer. Method • This retrospective study was conducted between January 2012 and May 2021. • Patients with HER2-positive advanced breast cancer who were treated using trastuzumab monotherapy or trastuzumab concomitantly with any dose of a BB were recruited and divided into three groups. • One group received only the trastuzumab (BB−/trastuzumab+), another group received both BB+ (non-selective) and trastuzumab [BB+ (non-selective)/trastuzumab+], and the third group received both BB+ (selective) and trastuzumab [BB+ (selective)/trastuzumab+]. • The PFS and OS were determined and compared between the treatment groups. Results • We enrolled 221 patients (mean age: 56.1 ± 11.1 years) in the study. • The estimated median PFS and OS were significantly lower in the BB+ (non-selective)/trastuzumab+ and BB+ (selective)/trastuzumab+ groups than in the BB−/trastuzumab+ group. • The use of BBs was associated with worse PFS and OS in patients with HER2-positive advanced breast cancer. Conclusion • Trastuzumab treatment was independently associated with poorer PFS and OS for patients who used BB prior to initiating trastuzumab therapy for advanced HER2-positive breast cancer. • BB use potentially has a negative effect on patients with HER2-positive advanced breast cancer. • Future studies with larger sample sizes are needed to validate our findings.