20. Oocytes Freezing in Patient with Cancer
Ovarian tissue cryopreservation was first performed more than 20 years ago. The first live birth after ovarian tissue transplantation after cryopreservation was reported in 2004  followed by a second one the following year . Today, with more than 120 live births and a 30% success rate, this technique is no longer considered experimental. However, the evolution of oocyte and embryo vitrification techniques has limited the ovarian cryopreservation to a selected number of patients. The ASRM (American Society for Reproductive Medicine) recognizes the cryopreservation of oocytes and embryos as only valid methods for the preservation of fertility.
Premature ovarian failure (POF) can occur in woman spontaneously or due to iatrogenic causes. Chemotherapy and radiotherapy have significantly increased life expectancy in cancer patients but at the same time they can become deleterious for the ovarian function and reserve.
The low-risk group includes:
The medium-risk group includes:
The high-risk group includes:
procarbazine (Fig. 20.1)
Cyclophosphamide is the agent which causes the greatest damage to oocytes and granulosa cells. The ovarian damage depends on patient’s age and on the type of treatment administered.
Three options can be proposed to preserve fertility before radiotherapy or chemotherapy: oocyte cryopreservation, embryo cryopreservation, and ovarian tissue cryopreservation. The vitrification of oocytes (in metaphase II) is the ideal technique in pubertal and adult age for the preservation of fertility in cases of benign diseases such as autoimmune diseases or in cases of neoplasia. Moreover, it is the only method that guarantees that no malignant cell is reintroduced when the oocytes will be used again. The embryo cryopreservation would be a better option because of the known oocyte loss at thawing but it requires the presence of a partner or donor sperm. Studies show a survival rate of mature oocytes after thawing of 90% and a 50% pregnancy rate. However, we must consider that in order to have a live birth, it is necessary to have at least 20 vitrified oocytes . In both cases, the patient must be in pubertal age and the start of the chemotherapy has to be postponed for 2 weeks, the time interval needed to stimulate the ovaries and collect mature oocytes. In prepubertal patients or in patients with oncological diseases in which the beginning of chemotherapy cannot be delayed, ovarian tissue cryopreservation represents the only possibility of preserving fertility.
Indications for cryopreservation of ovarian tissue in case of malignant and nonmalignant diseases (adopted from Donnez et al. )
(a) Extrapelvic diseases
Bone cancer (osteosarcoma and Ewing sarcoma)
(b) Pelvic diseases
Non gynecologic malignancy
Early cervical carcinoma
Early vaginal carcinoma
Early vulvar carcinoma
Selected cases of ovarian carcinoma (stage IA)
Borderline ovarian tumors
(c) Systemic diseases
(a) Uni/bilateral oophorectomy
Benign ovarian tumors
Severe and recurrent endometriosis
BRCA1 or BRCA2 mutation carriers
Causes of ovarian cryopreservation 
Benign and borderline ovarian pathology