Fertility preservation with random-start controlled ovarian stimulation and embryo cryopreservation for early pregnancy-associated breast cancer.

We report a case of fertility preservation using random-start controlled ovarian stimulation (COS), intracytoplasmic sperm injection (ICSI) and embryo cryopreservation in a patient with early pregnancy-associated breast cancer. A 34-year-old nulliparous woman at 5 weeks of gestation was diagnosed with estrogen receptor (ER) positive, progesterone receptor (PR) positive and human epidermal growth factor receptor-2 (HER-2) negative infiltrating intraductal carcinoma. Urgent neoadjuvant chemotherapy was deemed necessary and the patient decided to terminate the pregnancy.