Nov. 17, 2009 -- The prospect of a woman regrowing her own breast tissue following a mastectomy may be a welcome one, but some experts say initial reports on new trials underway to do that with stem cells in the U.K. and Australia have presented an overly rosy outlook.
British, Australian and American news outlets reported last week that groups in Melbourne and London had begun trials to use fat stem cells, derived from fat tissue from a patient's body, to rebuild a woman's breast following surgery. But while some predicted that the treatment would be available within a few years, that estimate ignores many of the safety concerns that accompany this type of research.
"I would be careful to jump on this as the cure for breast reconstruction," said Dr. Anne Wallace, director of the University of California, San Diego's Cancer Center's Breast Cancer Unit. "That is something where reconstruction avenues are already extremely well developed."
Wallace noted that present methods -- often involving implants, have positive results for many women, so the novelty of this method may be outweighed by both the potential cost and safety concerns.
"It's very exciting and an interesting avenue for reconstruction, but I want to wait for more to come out about it," she said.
Claire Nixon, senior editor for the nonprofit breast cancer information organization breastcancer.org, is herself a breast cancer survivor, having had a mastectomy to remove a tumor she found on a self-exam when she was 30.
She had immediate implantation at the same time, to avoid a period with no breast -- a benefit that she noted would not be had by women who may someday choose stem cell regrowth, a process that will take weeks or months.
"Women are really going to have to think about whether they want to do that wait or whether they want something right away. I can see a lot of reasons for wanting something right away," said Nixon.
At the same time, she said, "I think some women might find that exciting, that it can be their own tissue. An implant alone doesn't feel as natural as using your own fatty tissue from other parts of your body," she said, referring to a current operation where fat tissue from donor sites on the body is used to reconstruct the breast.
However, Nixon said, "I can't speak for all women, but for me, while it does sound very intriguing and compelling, I think that we need some long-term safety data first to ensure that there is a low risk of possibly regenerating any stray breast cancer cells."
That is one concern of researchers working on the new method. Professor Kefah Mokbel of the London Breast Institute told The Times in the U.K. that patients in his trial would need to be free of cancer for two years.
Mokbel did not reply to a message left at his office by ABCNews.com.
Wallace noted that she had some discomfort with the method because of the growth of stem cells and the possibility for spreading cancer, something that could delay the time from testing to availability, since long-term safety trials will, obviously, take years to complete.
"Until that's done, I'd be very uncomfortable," said Wallace. "It's not enough time to know."
Stem Cells in the U.S.
Dr. Grant Carlson, who is both a surgical oncologist and a plastic surgeon at the Emory University School of Medicine, said that another delay for patients in the United States hoping to use these stem cells might come from the Food and Drug Administration.
"The FDA has concerns adipose-derived stem cells are a drug," he said, meaning they would need approval before trials could begin here.
"In the United States, this is a huge leap because these patients have breast cancer and we're still a little unsettled about the use of adipose-derived stem cells. We don't have a whole lot of good data."
So while researchers in the new trials may believe their treatments are a few years off, it may be some time before the U.S. would approve trials.
"We're probably a few years away from the FDA making that decision about adipose-derived stem cells," said Carlson.
He noted, however, that one red flag in the current trials was that animal data they were relying on did not appear to be in the medical literature.
One other researcher contacted by ABCNews.com declined to comment on the record because of a lack of peer-reviewed data, and pointed to two papers by the group running the Australian stem cell trial -- one at the Bernard O'Brien Institute of Microsurgery in Melbourne -- that had been retracted from their journals. ABCNews.com found at least one additional retracted paper by the group since 2005.
As of press time, professor Wayne Morrison, the head of the group, had not responded to a request from ABCNews.com for comment.
Building A Better Breast?
Dr. Peter Rubin, a plastic surgeon at the University of Pittsburgh, received a three-year grant from the National Cancer institute in 2006 to explore using adipose stem cells to regenerate lost tissue, and has since had that grant extended through 2012.
"This is a technology that's been rapidly evolving. I'm not surprised that we're getting to that point," he said of the British and Australian trials to regrow breast tissue. "I'm hoping that we're going to see promising results from this."
While he acknowledged that some women may prefer the speed of an implant, he noted that long-term, breast regeneration may have advantages.
"Long-term, that is going to have a better look and feel than an artificial implant reconstruction, and it will have less problems as well," said Rubin.
Tumor growth caused by stem cells may also be an issue, he acknowledged, but a lack of cell growth is one more frequently encountered by researchers.
"The bigger problem is that we have trouble getting the tissues to grow and maintain their shape and volume," said Rubin.
Ultimately, he said, we should be able to regenerate tissue with stem cells. What is less clear is whether that will come from the current trials.
"There's such a broad body of literature about fat stem cells and the ability of those cells…to play a positive role in regenerative medicine applications," he said of the retractions issued by the Morrison Group. "They're not the only people doing that stuff."
"I believe this is a promising field," Rubin said. "Whether or not that strategy is the right one, we will find out."