Ovarian tissue freezing prior to chemotherapy
|Patients must be counseled that the use of preserved ovarian tissue to achieve pregnancy is not yet considered to be a routine clinical practice.||B|
|Ovarian tissue must be tested for the presence of cancer cells or markers.||B|
Ovarian tissue cryopreservation is an investigational technique.
For young women at high risk of ovarian failure, or for whom other options may not be suitable, ovarian tissue storage may be considered.
Ovarian tissue excision of part of one ovary (or occasionally a whole ovary) may be considered in young women who have a high risk of premature ovarian failure from their cancer treatment.
The process requires extensive counseling with a fertility specialist (and also a fertility counselor if appropriate), followed by a laparoscopic procedure to remove the tissue, which is then sliced up into very small segments and frozen. If a young woman subsequently suffers from permanent ovarian failure, the tissue slices can be grafted back into the pelvis and/or ovarian remnant. After 4 to 9 months the grafted tissue starts to function, with the development of follicles which contain oocytes and produce hormones. In some cases, spontaneous fertility is restored but often IVF is required to obtain oocytes, which are then fertilised and transferred.
The ovarian tissue should be assessed histologically and by other techiniques specific for the particular type of cancer (e.g. immunohistochemistry or molecular testing) for the presence of cancer cells or markers, both at the time of tissue excision and prior to grafting to minimise the risk of tumour cell transmission in the graft.
Likelihood of success
Currently this process of restoring fertility with creation of usable embryos must be considered investigational. Most reports detail restoration of ovarian function, but obtaining good quality embryos is extremely labour-intensive with high attrition rates and usually many attempts are required. Although over 14 births have now been reported from this technique, achieving a pregnancy cannot yet be viewed as a certain outcome.
Risks and side effects
Any laparoscopic technique is associated with a small risk of complications, such as infection, bleeding and perforation of bowel, bladder or blood vessel. The risk of a life-threatening complication is extremely remote.
The anesthetic risk may be significant in a patient who has a large mediastinal mass. There is also a theoretical risk of tumour cell transmission in the grafted tissue. This has been demonstrated in investigational models. The risk is minimised by comprehensive assessment of slices of the tissue by the techniques most appropriate for each particular tumour type.
The cost of the retrieval procedure and the grafting procedure is that of any laparoscopic surgery. The tissue processing, histological and other testing is negotiated with the individual institution performing the testing. In some institutions there will be a yearly storage fee for the ovarian tissue.
Future options for ovarian tissue grafting
Currently there are investigational models for ‘whole ovary’ cryopreservation, but this is not yet offered as routine clinical procedure.
Table 4: Comparison of fertility preservation options for females
|Egg freezing||Embryo freezing||Ovarian tissue freezing|
|Time required||12-17 days||12-17 days||½ day|
|Survival rates after freezing||60%||80%||Reasonable|
|Expectation of success||Good if get enough eggs||Excellent if get enough embryos||Low currently|
- Meirow D, Ben Yehuda D, Prus D, Poliack A, Schenker JG, Rachmilewitz EA, et al. Ovarian tissue banking in patients with Hodgkin's disease: is it safe? Fertil Steril 1998 Jun;69(6):996-8 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/9627281.
- Kim SS, Radford J, Harris M, Varley J, Rutherford AJ, Lieberman B, et al. Ovarian tissue harvested from lymphoma patients to preserve fertility may be safe for autotransplantation. Hum Reprod 2001 Oct;16(10):2056-60 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/11574491.
- Shaw JM, Bowles J, Koopman P, Wood EC, Trounson AO. Fresh and cryopreserved ovarian tissue samples from donors with lymphoma transmit the cancer to graft recipients. Hum Reprod 1996 Aug;11(8):1668-73 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/8921114.
- Bittinger SE, Nazaretian SP, Gook DA, Parmar C, Harrup RA, Stern CJ. Detection of Hodgkin lymphoma within ovarian tissue. Fertil Steril 2011 Feb;95(2):803.e3-6 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/20801440.
- Levine J, Canada A, Stern CJ. Fertility preservation in adolescents and young adults with cancer. J Clin Oncol 2010 Nov 10;28(32):4831-41 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/20458029.