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Preservation of fertility in premenopausal patients with breast cancer.

INTRODUCTION
Cancer survivorship is increasingly important with advances in cancer therapeutics. Minimisation of treatment-related morbidity is an area that requires attention. This situation is most pressing in premenopausal patients with breast cancer, in whom advances in hormonal and targeted therapies have improved mortality rates. However, treatment-related infertility is still poorly addressed, and in East Asia, there is limited discussion regarding management of treatment-related infertility.


METHODS
A search of the literature was conducted using PubMed, Google Scholar, and Science Direct using the terms "breast cancer", "fertility preservation", "oocyte and embryonic cryopreservation", "GnRH-a co-administration", "ovarian tissue cryopreservation and transplantation", "Japan", "China", "Korea", and 'Singapore". Only studies published in English from 1980-2019 were included. The focus of the review was on identifying the current fertility preservation methods available to premenopausal women with breast cancer and the barriers that impede access.


RESULTS
Fertility preservation options include GnRH-a co-administration to minimise treatment-associated infertility, oocyte and embryonic cryopreservation, and emerging treatments such as ovarian tissue cryopreservation and transplantation. In East Asia, the uptake of fertility preservation options has been limited despite it being a major patient concern. A lack of awareness of fertility preservation treatments hinders discussion between patients and clinicians about fertility preservation.


CONCLUSION
Despite progress in fertility preservation technologies, their impact for patients will be minimal if there is a lack of awareness/use of the technology. This review aims to raise awareness of such technologies among clinicians, enabling discussion between patients and clinicians about fertility preservation options.