Anti-estrogen Therapy and Fertility Preservation in Premenopausal Breast Cancer Patients: a Review

Purpose of Review Chemotherapy and anti-estrogen therapy have improved the life expectancy of young women who develop breast cancer. However, these agents can accelerate age-related ovarian follicle loss and diminish systemic estrogen levels. Although future fertility is an important issue for most young women, pregnancy rates are lower than expected in breast cancer survivors when compared with those of the general population. There may be little discussion regarding fertility preservation at the time of initial diagnosis. Greater knowledge of fertility preservation options will facilitate these discussions between oncologists and their patients. While strategies such as oocyte and embryo cryopreservation are available, they are affected by partner status, patient motivation, and economic factors. Gonadotropin releasing hormone (GnRH) analogues to protect ovarian reserve have been used due to their wide availability and potential ability to protect ovarian function, hence maintaining fertility in premenopausal women. The efficacy of this treatment, however, remains somewhat controversial. With the improved disease-free survival in premenopausal women with breast cancer demonstrated in multiple studies, women in this group are in need of better and more individualized strategies for fertility preservation. Recent Findings Current treatments have improved survival in young premenopausal women diagnosed with breast cancer. Multiple assisted reproductive techniques are available to patients who desire pregnancy including embryo cryopreservation, oocyte cryopreservation, ovarian tissue cryopreservation, and the use of GnRH agonists for ovarian function preservation. Recent studies have shown that pregnancy after breast cancer diagnosis and treatment is safe even with the use of medications to induce ovulation or in vitro fertilization (IVF) and can be accomplished without necessarily increasing risk of an adverse outcome. However, multiple barriers including lack of knowledge of the options available and fear of an adverse outcome as well as increased financial burden can be obstacles. Recent progress in the oncofertility field highlights the importance of addressing fertility concerns in young cancer patients in the treatment landscape. It is imperative that oncology providers discuss oncofertility options with their patients and become familiar with these techniques to offer a comprehensive and personalized approach to patient care.