Spironolactone can be used off-label for androgenic alopecia; however, little is known about the safety of this treatment in breast cancer survivors, and it has been speculated that it could increase the risk of breast cancer recurrence due to its estrogenic effects. A study found that spironolactone was not independently associated with an increased recurrence of breast cancer and is a viable treatment optionfor hair loss in breast cancer survivors. The results of the study were published as part of the American Academy of Dermatology Virtual Meeting Experience 2020.
Researchers retrospectively assessed the Humana insurance database and identified breast cancer survivors via International Classification of Diseases, 9th and 10th revision (ICD) codes. Patients were categorized by spironolactone prescription: Among 29,146 females with a history of breast cancer, 746 were prescribed spironolactone—733 were prescribed spironolactone within one year of diagnosis and 13 were prescribed it within one to two years of diagnosis. Cohorts were further matched 1:1 using propensity score analysis.
Spironolactone was not associated with increased risk for breast cancer recurrence within two years (primary outcome) after adjusting for patient characteristics. Breast cancer recurrence occurred in 16.5% of patients (n=123) treated with spironolactone compared with 12.8% (n=3,649) who were not (P<0.005). This finding is similar to what previous studies have shown.
In multivariate analyses, the hazard ratio (HR) for unadjusted pre-match breast cancer recurrence was 1.08 in patients treated with spironolactone (95% confidence interval [CI], 0.95-1.23; P=0.227).
Moderate alcohol consumption has been associated with an increased breast cancer risk in previous studies due to increased estrogen levels, interference with antioxidative defense systems and DNA repair, and possible downregulation of the tumor suppressor BRCA1. In this analysis, the HR for hypertension was 1.16 (95% CI, 1.10-1.21; P<0.001) and alcohol abuse was 1.30 (95% CI 1.08-1.55; P=0.005).
The study is limited by its retrospective design and use of ICD codes. Long-term prospective studies should be performed to confirm the study’s findings, according to the researchers.
Wei C, Bovonratwet P, Silverberg JI, et al. Spironolactone use does not increase the risk of estrogen‐dependent cancer recurrence: A retrospective analysis. Presented during the AAD Virtual Meeting Experience 2020, June 12-14, 2020.