Pioneering research seeks to preserve fertility in boys and young men who undergo childhood cancer treatment.
Treatment for cancer, including chemotherapy and radiotherapy, can compromise the ability to make sperm. While sperm can be collected and frozen prior to cancer treatment in males who have gone through adolescence, this is not an option for pre-pubescent boys, who do not yet make sperm. With childhood cancer on the rise in Scotland, finding an option to treat infertility later in life is increasingly becoming a priority. Now, a team at the MRC Centre for Reproductive Health at Edinburgh University led by Professor Rod Mitchell, hopes to get permission to start clinical trials for a treatment, named testicular cryopreservation, early next year.
'We are all very excited about it', said Professor Mitchell. 'The fact that we are about to embark on seeking approval to start trials is really positive news for the patients and their parents and carers involved in our research, who are generally very enthusiastic about the programme'.
Over the last five years, researchers at the MRC Centre for Reproductive Health at Edinburgh University have been focusing on freezing biopsies of healthy testicular tissue taken from children prior to cancer treatment, in the hope that the tissue can be re-implanted later in life to restore fertility.
If successful, the resulting sperm could be extracted and used in assisted reproductive technologies.
Preliminary studies in animals show promising results, with a trial of the technique on monkeys leading to the birth of a baby rhesus macaque called Grady in the USA in 2019 (see BioNews 992).
In a talk at the recent Progress Educational Trust (PET) event 'Advances in Assisted Reproduction: What Can We Expect' (see BioNews 1119), Professor Mitchell highlighted how pubescent boys, whom he termed the 'inbetweeners' are somewhat in limbo between testicular cryopreservation and sperm cryopreservation. Patients of these ages are likely to become the focus of fertility preservation trials in the future.
Ovarian tissue cryopreservation has been used for over 25 years in pre-pubescent girls prior to cancer treatment and has proven successful as a treatment for infertility later in life. Data from this has been important in guiding the selection criteria for testicular cryopreservation in pre-pubescent boys.
Sarah Norcross, director of PET, the charity which publishes BioNews, said 'This is an ingenious method of seeking to restore male fertility, and could be of immense benefit to men whose fertility has been lost or compromised during childhood or adolescence, either by disease or by treatment for disease... Reproductive options for men in this predicament have been severely limited, but now there is real hope this situation could change. Careful work will now need to be done to assess and refine these new techniques but the fact that this work is now sufficiently advanced to embark on clinical trials is a remarkable achievement'.