Men left infertile by childhood cancer were given new hope today with two major scientific breakthroughs.
For the first time, researchers have developed a type of testicular transplant which could give teenage cancer patients the chance of fatherhood in later life.
Even babies and very young boys who develop cancer could have their fertility preserved by the procedure, revealed for the first time in the journal Human Reproduction.
The procedure is similar to that currently being used to transplant ovaries, giving hope to infertile women.
In a separate study, researchers at University College Hospital in London have found that they can also give teenage cancer patients the chance to have children in later life by successfully collecting sperm samples - previously thought impossible.
Cancer charities hailed the breakthroughs as a "great step forward" for young boys who have to face the dual trauma of cancer and the loss of their chance of fatherhood at the same time.
It is the first time that boys with the disease have been offered the hope of being able to have children following cancer treatment. Around 500 teenage boys develop cancer every year in the UK. While survival rates have increased in recent years, many are left infertile by the aggressive chemotherapy treatment needed to save them.
In the first study, Japanese scientists from Kyoto University have achieved a world first by taking and freezing testicular tissue from healthy mice, then thawing and implanting it into other mice whose sperm has been destroyed by injections of cancer drugs.
The healthy, grafted tissue kickstarted sperm production in the affected mice. The scientists then extracted the sperm and successfully impregnated 123 female mice.
The scientists hope to be performing the technique in humans within 10 years, and say that even baby boys could be treated successfully.
In the second study, scientists from University College say that sperm samples can now be taken from boys as young as 12. Older men who are diagnosed with cancer are now routinely offered the chance of having sperm samples taken from them which can then be frozen and used in fertility treatment, but it was thought this was impossible to perform in adolescent boys because the samples could not be successfully preserved.
But the UCL scientists found that boys who had gone through puberty were able to produce samples which could be preserved and frozen for later treatment.
Lead researcher Dr Gulam Bahadur said: "This high level of success should reassure doctors, parents and in particular patients. These young people are having to embark on chemotherapy or radiotherapy that is probably going to damage or even destroy their ability to father children.
"Now we can provide them with some positive news that will give a much-needed psychological boost at a difficult time in their lives."
Dr Bahadur said some IVF clinics may now have banked sperm taken from teenage boys to be used in later life.
Myrna Whiteson, chair of the Teenage Cancer Trust, welcomed the news, saying: "There is a lot that we still need to understand both physiologically and psychologically about adolescents and young people with cancer and this will not be a solution for every boy.
"However, it is a great step forward and one that the Teenage Trust very much welcomes."Reuse content