The aromatase inhibitors (plus ovarian function suppression) in premenopausal breast cancer patients: ready for prime time?

Tamoxifen alone or the combination of ovarian function suppression (OFS) and tamoxifen are the mainstay of hormonal therapy in premenopausal women with endocrine-responsive breast cancer. The results of large trials conducted with the third generation of aromatase inhibitors (AIs) in the metastatic, neoadjuvant and adjuvant setting, indicated better outcomes among postmenopausal breast cancer patients with endocrine responsive disease given AIs than among those given tamoxifen. These results supported the investigation of AIs in combination with OFS in premenopausal women with hormone receptor positive breast cancer. In this article we reviewed the efficacy and toxicity data on the use of AIs combined with OFS in premenopausal breast cancer patients in metastatic, neoadjuvant and adjuvant setting. Given the available evidence at the time in metastatic setting for premenopausal patients suitable of endocrine therapy the AI is a viable option, if tamoxifen resistance is proven, although mandates the use of OFS. In neoadjuvant setting the AIs in combination of OFS should not be used outside of a clinical trial. In the adjuvant setting, tamoxifen alone or OFS plus tamoxifen are reasonable options. Despite the lack of conclusive data favoring the combination of tamoxifen plus OFS, this treatment might be a reasonable option for subgroups of patients such as very young patients, OFS alone should nort be considered unless tamoxifen was contraindicated. Similarly, in cases where tamoxifen is contraindicated, AIs as an adjunct to OFS is a treatment option in premenopausal patients. New large randomized studies are required to confirm the role of OFS plus an AI in premenopausal women.