23 August 2007

Freeze ovaries before chemo

Japanese researchers have successfully removed, frozen and put back the ovaries of monkeys, raising hopes that women treated for cancer can still have a natural pregnancy.

Japanese researchers, on Thursday, said that they have successfully removed, frozen and put back the ovaries of monkeys in a process raising hopes that women treated for cancer can still have a natural pregnancy.

Adapting a freezing method which the Japanese use to preserve tuna, the researchers took out both ovaries from five monkeys and froze them for up to three weeks before re-inserting them.

Tadashi Sankai, chief researcher at the National Institute of Biomedical Innovation's primate laboratory, said they were now also studying freezing other organs such as the heart and liver, as well as the skin.

Producing estrogen again
The researchers confirmed the returned ovaries in two of the monkeys were producing estrogen, the hormone needed to grow eggs in the female body.

If adapted to humans, the new method would spare the organ from possible damage during chemotherapy or other cancer treatment.

"A big benefit is that they would be able to become pregnant naturally," Sankai told AFP.

Currently, the options for female cancer patients who want to have a child in the future include freezing their eggs for external fertilisation.

Sankai said researchers will study if the monkeys in the experiment produce healthy eggs.

Will eggs function properly?
"We are planning to examine if eggs will grow properly," he said, adding researchers would test the eggs by taking them out for in vitro fertilisation.

It is difficult to freeze a substance containing a lot of water, but the team applied a freezing method used in far-seas fishing to preserve tuna, which the Japanese eat raw as sashimi after thawing.

After freezing the ovaries, the researchers kept them in liquid nitrogen at minus 196 degrees Celsius for two to three weeks. – (Sapa)

Read more:
Freezing ovaries for later
Preserving fertility beyond cancer


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