Fertility preservation in oncology.

Survival rates of childhood and pre-pubertal female cancer patients are constantly increasing. However the lifesaving treatments carry a significant risk for infertility. Chemotherapy and radiotherapy might induce oocyte and follicular loss, infertility and premature ovarian failure. In order to preserve the fertility potential, several options are currently available, many of those should be considered as experimental. Ovarian transposition out of the radiation field may considerably reduce the radiation dose and should be considered for patients younger than 40 years of age. The benefits of GnRH analog are not clear yet and apoptosis inhibiting agents are not available. Embryo cryopreservation is a well established technique and should be offered to patients with spouses; when the patient does not have a male partner, oocyte cryopreservation or vitrification can be performed. When the cancer treatment cannot be delayed for ovarian stimulation or the tumor is hormone sensitive then collection of immature oocytes from unstimulated ovaries is particularly useful. The oocytes are matured in-vitro and either fertilized and cryopreserved as embryos or vitrified as mature oocytes. Ovarian tissue cryopreservation has the potential of preserving thousands of primordial follicles. The thawed ovarian tissue can be autotransplented orthotopically or heterotopically. Until now, only one human live birth has been reported and critical issues like the potential risk of transplanting malignant cells and the survival of the grafts have to be addressed. The strategy for preservation of fertility prior to cancer treatment should be tailored according to the patients age, presence of a partner, type of malignant disease, therapeutic agent, and time interval available. The patient should obviously be informed that some of the methods are still experimental.