Cryopreservation of ovarian tissue for fertility preservation: no evidence of malignant cell contamination in ovarian tissue from patients with breast cancer.

Cryopreserved ovarian cortical biopsies from 51 patients with breast cancer were examined by histologic and immunohistochemical analysis and showed no sign of metastases. Autotransplantation of ovarian cortex to patients with low-stage breast cancer disease appears safe, but confirmatory studies are required, including xenotransplantation studies.