Fertility preservation in breast cancer patients

Breast cancer is the most common malignancy in women as it currently represents 15.2% of all new cancer cases in the United States with 268,600 estimated new cases in 2019 [1]. Under 45 years of age, the percentage of new cases is 10.3% as it is the most common of all in women of childbearing age. Due to the increasingly advanced diagnostic and therapeutic techniques, the mortality rate remains low in recent years. For stages I and II, the 5-year survival is estimated to be respectively 95% and 85–70% (depending on whether they are IIA and IIB), while in advanced stages, survival rates are between 18 and 52% (for stages IIIA and B) [1]. Because the number of young cancer survivors is increasing and as women tend to have children in later reproductive ages, increasing attention has been paid to chemotherapy-related ovarian toxicity [2]. Most women with breast cancer are likely to undergo neoadjuvant or adjuvant chemotherapy that may result in premature ovarian failure and infertility [3–5].