title: Vaginal estrogen products in hormone receptor-positive breast cancer patients on aromatase inhibitor therapy.
abstract: Atrophic vaginitis represents a major barrier to compliance with aromatase inhibitor (AI) therapy in breast cancer (BC) survivors. While local estrogen therapy is effective for postmenopausal vaginal dryness, the efficacy of such therapies has not been evaluated systematically in hormone receptor-positive (HR+) BC patients on AI therapy. Furthermore, the potential risk of breast cancer recurrence with vaginal estrogen therapy represents a long-term safety concern for the patients with HR + BC. Unfortunately, there is no standardized assay to measure very low concentrations of estradiol (E2) in these women being treated with AI therapy. This makes it difficult to evaluate even indirectly the potential risk of BC recurrence with vaginal estrogen therapy in HR + BC patients on AI therapy. In this review, we describe available assays to measure very low concentrations of E2, discuss the Food and Drug Administration-approved vaginal estrogen products on the market, and summarize published and ongoing clinical trials evaluating the safety and efficacy of vaginal estrogen in HR + BC patients on AI therapy. In the absence of any randomized controlled clinical trials, this review serves as a summary of available clinical data and ongoing studies to aid clinicians in selecting the best available option for their patients.
authors.affiliation: Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, 1441 Moursund St., Houston, TX, 77030, USA.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Sulaica
authors.affiliation: Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, 1441 Moursund St., Houston, TX, 77030, USA.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Han
authors.affiliation: Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, 1441 Moursund St., Houston, TX, 77030, USA.
authors.forename: Weiqun
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, 1441 Moursund St., Houston, TX, 77030, USA.
authors.forename: Raksha
authors.initials: R
authors.lastname: Bhat
authors.affiliation: Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, 1441 Moursund St., Houston, TX, 77030, USA. mtrivedi@uh.edu.|Lester and Sue Smith Breast Cancer, Baylor College of Medicine, Houston, TX, USA. mtrivedi@uh.edu.
authors.forename: Meghana V
authors.initials: MV
authors.lastname: Trivedi
authors.affiliation: Lester and Sue Smith Breast Cancer, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Polly
authors.initials: P
authors.lastname: Niravath
mesh_terms: D000282:Administration, Intravaginal; D047072:Aromatase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D059268:Atrophic Vaginitis / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy*; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000139:chemically induced*; D010349:Patient Compliance; D017698:Postmenopause; D017741:Survivors
chemical_list: D047072:Aromatase Inhibitors; D004967:Estrogens; D004958:Estradiol
keywords: Aromatase inhibitor; Breast cancer; Hormone receptor; Vaginal atrophy; Vaginal estradiol; Vaginal estriol; Vaginal estrogen; Vaginal symptoms