Spironolactone use does not increase the risk of female breast cancer recurrence: A retrospective analysis

Spironolactone is used off-label for androgenic alopecia because of its ability to arrest hair loss progression and long-term safety profile. However, little is known about the safety of spironolactone in breast cancer (BC) survivors. Because spironolactone has estrogenic effects, there is a theoretical risk for BC recurrence. Given that spironolactone is an important tool in the treatment of alopecia, we investigated whether spironolactone increased risk for BC recurrence.

To determine whether spironolactone is associated with increased BC recurrence.

A retrospective analysis was conducted using the Humana Insurance database. Patients with a history of BC were identified using International Classification of Diseases codes, stratified by spironolactone prescription, and also matched 1:1 using propensity score analysis. Patient characteristics and cancer recurrence rates between both cohorts were compared and analyzed.

BC recurrence developed in 123 patients (16.5%) who were prescribed spironolactone compared with 3649 patients (12.8%) who developed BC recurrence without spironolactone prescribed (P = .004). After propensity matching, adjusted Cox regression analysis showed no association between spironolactone and increased BC recurrence (adjusted hazard ratio, 0.966; 95% confidence interval, 0.807-1.156; P = .953).

Retrospective study.

Spironolactone was not independently associated with increased BC recurrence and may be considered for the treatment of alopecia in BC survivors.