Introduction: Breast cancer is the most frequent cancer among women with about 1.38 million new cases worldwide every year. Most of these patients are postmenopausal and suffer from hormone receptor positive breast tumors. About 50% of postmenopausal women between 50 and 60 years and 72% of women over 70 years suffer from vulvovaginal athrophy (VVA). Adjuvant treatment with aromatase inhibitors (AIs) improves outcomes in postmenopausal women with hormone receptor positive early stage breast cancer compared with tamoxifen. A frequent side effect of AI use is VVA with symptoms like vaginal dryness, vaginitis, pruritus, dyspareunia and cystitis.
Materials and methods: We searched major databases (i.e. pubmed) with the following selection criteria: breast cancer, hormone therapy, vaginal estrogen, aromatase inhibitor, vaginal atrophy, serum estrogen levels.
Conclusions: Vaginal administration of estradiol is a well known and safe alternative to systemic estrogen therapy, but studies demonstrated significant increases in plasma concentrations of estradiol. Such observations have also been reported in postmenopausal breast cancer patients treated with AIs. Further studies are needed to explore risk of breast cancer recurrence after vaginal estrogen application for patients on adjuvant endocrine therapy with AIs.