by Dr Agilan Arjunan
The month of October is dedicated for cancer awareness.
Pink October is a month for breast cancer awareness. There is considerable media attention on the issue of breast cancer and breast cancer survivors .
Thus, it is appropriate and also essential to dwell into a topic so important to all cancer survivors, yet seldom discussed, which is their fertility health preservation. Cancer treatment, specially chemotherapy, can potentially lead to sterility due to its effects on the gonads ( ovaries and testicles).
In recent years, we are seeing more cancer survivors , thanks to the advancement in diagnosis and treatment of all types of cancers. Many childhood and young cancer survivors live through their adulthood and their need to start a family warrants attention.
Typically, the discussion about any fertility preservation technique for a patient starts with their oncologist. The issue becomes more complicated if the patient is a minor. In this situation, parents usually decide in the best interest of their child after discussion with their oncologist and fertility specialist.
The suitability of each methods of fertility preservation depends on the type of cancer, the treatment regime, the time interval between diagnosis and treatment and the status of sexual development of the patient (i.e pre-pubertal vs post-pubertal).
Post-pubertal boys / Young adults
In post-pubertal boys and young adults, the most established method of fertility preservation is cryopreservation of their sperm . This is simply known as sperm freezing. Sperms that are frozen can be kept in liquid nitrogen for many years. Once the patient had overcome his struggles and ready to start a family, his sperm can be thawed and with the assistance of reproductive techniques , he can realise his hope of have his own child.
The usual method of obtaining sperm is by masturbation. If this is not possible, sperm can be obtained surgically from the epididymis or testicle (PESA / TESA). In selected cases, sperm can be obtained through electroejaculation done under sedation.
In cases where radiotherapy is the main treatment regime, the gonads (testicles) can be shielded from radiation field.
In this group, there is no established method of fertility preservation. Currently, testicular tissue can be frozen. In future, we hope to re-implant the testicular tissue for sperm production in humans. This method is still considered experimental in animals. Spermatogonial Stem Cells (SCC) from the testicular tissue has been re-implanted in the testicles of animal and higher primates and successful sperm production has been reported. In some, the testicular tissue itself has been re-implanted back in the testicles or even under the skin. Sperms are obtained after several weeks and pregnancy is possible via an IVF procedure. Hopefully in near future, this method will be successful in humans.
Post-pubertal girls / Young woman
In young girls and woman, they have started their menstrual cycle , which means the ovaries has started to produce ‘eggs’. In this situation , for a young woman, the most established method would be to undergo a stimulated hormonal cycle ( In-Vitro Fertilisation, IVF) to collect their eggs prior to cancer treatment. If they have a partner, embryos can be formed and cryopreserved. Just like the sperm, embryos can be cryopreserved for years till the woman is ready to use them. The method and success rate for embryo cryopreservation is well established.
However, in the event that the woman has no partner or in the case of a young girl, creating an embryo is not an option. In this scenario, instead of an embryo, their eggs can be cryopreserved. In recent years, the technology of cryopreserving eggs has improved so much that it gives a very good success rate . When the eggs are frozen, the woman would need an IVF and her eggs are fertilised with her partner’s sperm and the embryo is transferred into her womb for a successful pregnancy.
When radiotherapy is the mainstay of treatment, where applicable, the ovaries can be shielded from radiation field.
The other method of ‘shielding’ the ovary would be by performing ovarian transposition ( oophoropexy) laparoscopically. In this surgical procedure, the ovaries are moved from their original position and fixed in a position away from radiation field. This method does not protect the ovary from damaging effects of chemotherapy.
In cases where chemotherapy is needed and there is no time for egg or embryo cryopreservation, the woman can be given hormonal treatment (gonadotrophin releasing hormone agonist , GnRH agonist) prior to starting chemotherapy. This hormones will ‘shut down’ the ovary and the ovary may be less susceptible to the damaging effects of the chemotherapy.
However, the evidence for this method is still not strong.
Ovarian tissue cryopreservation and re-implantation has been tried for woman who are not suitable or decline other methods of fertility preservation. This method is also suitable when there is no time for egg or embryo cryopreservation.
In this technique, the outer layer of the ovaries , which contains immature eggs, is removed from the ovary and later re-implanted back . Pregnancy is then achieved using the IVF technology. To date, few live birth has been reported using this technique.
Many cancer treatments requires surgery . In an early stage of cervical cancer, fertility preserving surgery , known as radical trachelectomy, is an option. In this surgery, only the cervix which is affected by cancer cells are removed, preserving the uterus and ovary for future reproduction.
Similar to pre-pubertal boys, there is no well established method of fertility preservation technique in this group of patients.
If time permits, ovarian tissue can be biopsied laparoscopically for future re-implantation and pregnancy via an IVF.
However, this decision needs to be carefully explored after discussion with parents,oncologist and fertility specialist.
Even though there are few well established methods of fertility preservation for young cancer patients, this information needs to be made available to the patient and his / her family. Initial discussion should take place with patient’s primary doctor and where necessary, referral to a fertility specialist should be made. A multidisciplinary approach is needed to not only treat the cancer but to also ensure the cancer survivors lead a normal life including having their own family.