Spironolactone use is not associated with a statistically significant increased risk for breast cancer or other solid organ cancers and is associated with a decreased risk for prostate cancer, researchers reported in a study published in JAMA Dermatology.
The systematic review and meta-analysis was conducted after a search in PubMed, Cochrane Library, Embase, and Web of Science from inception through June 11, 2021. Eligible studies evaluated the risk for cancer in women or men aged 18 years or older who were exposed to spironolactone.
The analysis included 7 observational studies with 4,528,332 individuals. Participants’ mean age ranged from 62.6 to 72.0 years. In the studies that were not stratified by sex, the lowest percentage of women was 17.2%, and the highest percentage was 54.4%. All of the included studies had a low risk for bias.
In 3 studies, no statistically significant association was found between spironolactone use and risk for breast cancer (relative risk [RR], 1.04; 95% CI, 0.86-1.22; I2 = 85%), and the certainty of evidence was very low. In 4 studies, an association was observed between spironolactone use and a decreased risk for prostate cancer (RR, 0.79; 95% CI, 0.68-0.90; I2 = 74%), and the certainty of evidence was very low.
The risk for ovarian cancer was assessed in 2 studies (RR, 1.52; 95% CI, 0.84-2.20; I2 = 86%), with a low certainty of evidence. From 2 studies and 3 estimates that assessed the risk for bladder cancer (RR, 0.89; 95% CI, 0.71-1.07; I2 = 85%), the certainty of evidence was very low. The risk for kidney cancer was assessed in 2 studies and 3 estimates (RR, 0.96; 95% CI, 0.85-1.07; I2 = 30%), with a low certainty of evidence.
The risk for gastric cancer was assessed in 2 studies (RR, 1.02; 95% CI, 0.80-1.24; I2 = 0%), and the certainty of evidence was low. Also, 2 studies assessed the risk for esophageal cancer (RR, 1.09; 95% CI, 0.91-1.27; I2 = 0%), with a low certainty of evidence.
The investigators noted that the confidence intervals for the estimates are wide and they cannot entirely exclude the potential for a meaningful increase in cancer risk. In addition, the studies included mostly European and predominantly older individuals and all were in the English language. Furthermore, in sensitivity analyses, some differences were observed in the effect estimates depending on which studies were included, particularly for breast cancer.
“This systematic review and meta-analysis provides reassuring data that use of spironolactone, an important treatment for patients with acne, hidradenitis, androgenetic alopecia, and hirsutism, is unlikely to be associated with a substantial increased risk of cancer,” concluded the study authors. “However, the certainty of the evidence was low.”
Bommareddy K, Hamade H, Lopez-Olivo MA, Wehner M, Tosh T, Barbieri JS. Association of spironolactone use with risk of cancer: a systematic review and meta-analysis. JAMA Dermatol. Published online February 9, 2022. doi:10.1001/jamadermatol.2021.5866