Safety of 5α-reductase inhibitors and spironolactone in breast cancer patients receiving endocrine therapies Review


Authors: Rozner, R. N.; Freites-Martinez, A.; Shapiro, J.; Geer, E. B.; Goldfarb, S.; Lacouture, M. E.
Review Title: Safety of 5α-reductase inhibitors and spironolactone in breast cancer patients receiving endocrine therapies
Abstract: Purpose: To provide dermatologists and oncologists with a foundation for practical understanding and uses of 5α-reductase inhibitors and spironolactone for breast cancer patients and survivors receiving endocrine therapies (ETs), including the effect of these treatments on sex hormone levels, any reported drug interactions, and any risk of malignancy. Methods: All published studies from January 1978 through April 2018 were considered, using databases such as PubMed, Google Scholar, and Science Direct. Forty-seven studies were included in this review. Results: There is no evidence of interactions between 5α-reductase inhibitors and spironolactone with ETs used in breast cancer. Sex hormone alteration with 5α-reductase inhibitor or spironolactone use is variable. Three randomized controlled trials, 1 case–control study, and 6 retrospective cohort studies, including 284 female patients, studied the effects of 5α-reductase inhibitors on serum estrogen levels. Levels were increased in 97 of 284 (34%) patients, decreased in 15 of 284 (5.3%) patients, and unchanged in 162 of 284 (57%) patients. Four retrospective cohort studies, 1 case study, and 1 double-blinded crossover study, including 95 female patients, assessed the effect of spironolactone on estrogen levels. Levels were increased in 25 of 95 (26%) patients, decreased in 6 of 95 (6.3%) patients, and unchanged in 64 of 95 (67%) patients. Ultimately, most patients did not have a significant alteration in the level of estrogen when using 5α-reductase inhibitors or spironolactone. No consistent evidence of increased risk of female breast cancer while on spironolactone was reported in 3 studies including 49,298 patients; the risk of breast cancer with the use of 5α-reductase inhibitors has not been studied. Conclusions: Most patients did not show increased estrogen levels with spironolactone and there were no data suggesting increased risk of breast cancer. Based on hormonal and pharmacological activity, spironolactone may be considered for further research on alopecia and hirsutism in breast cancer patients. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Keywords: review; cancer recurrence; cancer risk; drug safety; systemic therapy; cancer patient; recurrence risk; breast cancer; estrogen; drug effect; cancer survivor; finasteride; hormonal therapy; dutasteride; spironolactone; drug use; endocrine therapy; steroid 5alpha reductase inhibitor; estrogen blood level; male type alopecia; human; priority journal; functions of the skin and its appendages; 5α-reductase inhibitors; female breast cancer; female pattern hair loss; hair cycle
Journal Title: Breast Cancer Research and Treatment
Volume: 174
Issue: 1
ISSN: 0167-6806
Publisher: Springer  
Date Published: 2019-02-01
Start Page: 15
End Page: 26
Language: English
DOI: 10.1007/s10549-018-4996-3
PUBMED: 30467659
PROVIDER: scopus
PMCID: PMC6773272
DOI/URL:
Notes: Review -- Export Date: 1 April 2019 -- Source: Scopus
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  1. Mario E Lacouture
    457 Lacouture
  2. Shari Goldfarb
    151 Goldfarb
  3. Raquel Rozner
    4 Rozner
  4. Eliza Brevoort Geer
    50 Geer