MELBOURNE surgeons have partially succeeded in regrowing breast tissue using a patient's own fat cells in one of five women involved in a pilot trial after cancer surgery.
Surgeons implanted each woman with an acrylic breast-shaped chamber, into which they redirected blood vessels attached with the patient's fat cells from under her arm.
The technique, called Neopec, has been tested on five women over the past 18 months in the hope it could help them regrow breasts after a mastectomy, as an alternative to silicone implants.
Head of the research team at the Bernard O'Brien Institute of Microsurgery, Professor Wayne Morrison, said there was no tissue regeneration in three patients, and one had to withdraw from the trial after pain from the acrylic chamber pressing on her ribs.
But tissue did regrow to fill the breast-shaped chamber in the fifth patient, in what Professor Morrison said was an exciting result that proved the concept could work in humans. He said his team implanted the woman with 30 cubic centimetres of fat cells, which grew to 180 cubic centimetres over a year to fill the acrylic chamber, before it was removed.
''She's quite small in the first place and a 180cc breast is a small breast, but she is happy with the outcome and does not want any added implant to augment her further,'' Professor Morrison said.
''One of the things cosmetically that's probably marred the appearance slightly is that … the chamber had become scarred and embedded into the chest, so it flattened it down.''
Doctors were monitoring the woman to determine whether she retained the regrown tissue, he said.
''One of the issues was that it wasn't all fat tissue growing, it was mostly fibroblastic tissue, which is used to heal wounds,'' he said. ''We would wonder in the long-term whether it would be adequate for permanent replacement, though we did review her three months later and the volume was stable, so it is very encouraging.''
All of the women in the trial had undergone mastectomies and were unsuitable for surgery to transfer tissue from their stomach to their breast.
Patients who did not achieve tissue regeneration, which was apparent on MRI scans, had breast reconstructions using silicone implants at the same time as the surgery to remove the acrylic chambers.
One of those patients was Andrea Bolton, 50, who said she was pleased with her silicone implant and philosophical about having undergone additional surgery as a result of her involvement in the trial.
''Chemo[therapy] for breast cancer is so good now and I always believe in the pay-it-forward thing,'' she said. ''There were people years ago who put that horrible toxic poison in their bodies for the first time not knowing what the end result would be - so I think if you can give back on something that will help others down the track, you should.''
Now in good health, she said she hoped researchers would further develop the technique to give women more options after breast cancer surgery, ''and I know they will''.
Professor Morrison said further basic research was required before his team could justify more human trials, and work was under way to develop injectable gels that could form fat tissue without the need for an acrylic chamber.
''Although not every patient succeeded, the fact that one has grown tissue to the extent it completely filled the chamber is an extremely positive finding that has given us great enthusiasm and direction and potential for this,'' he said.
Professor Morrison said the trial had been unaffected by the collapse of partner organisation the Australian Tissue Engineering Centre, after claims of accounting discrepancies in the company's spending on Neopec. He said the project - which received a $2.95 million state government grant - had been ''fully funded'' and audited by a government department.