Two new research studies have been published in the journal Human Reproduction which 'brings new hope of preserving fertility for boys who face sterility after cancer treatment'.
In the first study, a Japanese team report that they have enabled mice to be born from frozen immature testicular tissue taken from one set of mice and matured in others. They also report that a rabbit was born using semen from testicular material that was matured in a mouse. The mice used to host the tissues had their own sperm destroyed in a way which mimicked damage from cancer treatment. The transplanted testicular tissue grew in the host mice and began to produce sperm, which in each case was injected into recipient eggs of the relevant species. Sixty-two mice were born from 123 embryos implanted into surrogates. One rabbit was born following embryo transplants into two surrogate hosts.
Dr Atsu Ogura, lead author of the Japanese team, said that the research showed 'that immature testicular tissue transplanted into hosts can develop, that we can obtain mature sperm and achieve live births. This gives hope that in the future we will be able to restore fertility even to pre-pubertal boys and babies'.
The second study shows that it is possible to obtain semen from boys as young as 12 and the authors, a team of British researchers, call for sperm banking to be offered to all cancer patients from that age. The team, led by Dr Gulam Bahadur of University College Hospital, London, studied 238 boys about to undergo cancer treatment, and 71 healthy boys. They found that 85 per cent of the boys aged from 12 onwards were able to produce a viable sperm sample that could be cryopreserved.
Dr Bahadur said 'this is an important and heartening finding. Adult patients are routinely offered pre-treatment sperm cryopreservation. But, this facility has only recently begun to be offered to adolescents and not much is known about the quality of the semen in this age group and its feasibility for freezing'.