A type of breast implant linked to a rare cancer can still be sold in the United States, even though it has been banned in many other countries, the Food and Drug Administration said on Thursday.
The implants, which have a textured or slightly roughened surface, as opposed to a smooth covering, have been associated with a cancer of the immune system called anaplastic large-cell lymphoma.
The vast majority of the cases have occurred in women with textured implants, mainly those made by Allergan. But the F.D.A. said that the risk, though increased, was still low, and that there was not enough data to justify banning the implants.
It also said that in some patients with lymphoma, the type of implant was not known, so smooth implants could not be ruled out as a cause.
Dr. Mark Clemens, a plastic surgeon and expert on the lymphoma at the M.D. Anderson Cancer Center in Houston, said the disease was linked exclusively to textured implants. He said there were no known cases of the lymphoma anywhere in the world in a woman who had only smooth implants. Some cases had occurred in women with smooth implants, he said, but they previously had textured ones.
He described the F.D.A. as “erring on the side of being conservative.”
Worldwide, he said, there have been more than 600 cases of the lymphoma, and about 20 deaths. In the United States, there were 265 reported cases. About 10 million women around the world have implants, which are used for cosmetic breast enlargement, or for reconstruction after mastectomy for breast cancer.
Only about 10 percent of the implants used in the United States are textured, but in other countries the figure can be as high as 80 percent.
The agency’s announcement followed a two-day public hearing in March, in which researchers and implant makers presented data, and women described a number of illnesses they developed after getting implants, including the lymphoma.
The F.D.A. statement acknowledged that in some women, implants may be associated with systemic problems called “breast implant illness,” which includes a constellation of symptoms like chronic fatigue, pain, cognitive and immune problems.
“While the F.D.A. doesn’t have definitive evidence demonstrating breast implants cause these symptoms, the current evidence supports that some women experience systemic symptoms that may resolve when their breast implants are removed,” the agency said in a statement.
It was issued by principal deputy commissioner, Dr. Amy Abernethy, and Dr. Jeff Shuren, director of the center for devices and radiological health. “We believe women considering a breast implant should be aware of these risks.”
Agency officials pledged to take action to make sure that both women and health care providers are better informed about the risks. The statement said the F.D.A. would consider requiring a black-box warning — its most serious — for the products and requiring that doctors go over a checklist with patients describing implant risks as part of the informed consent process before surgery. But the agency did not commit to these actions.
Jamee Cook, co-founder of Breast Implant Victim Advocacy, said she was disappointed that textured implants will not be banned. But she welcomed the F.D.A.’s proposals to ensure patients are better informed about the potential risks of breast implants.
“There is information in the manufacturer’s pamphlet, but it is 40 or 60 pages long,” Ms. Cook said. “Pulling it all together on a piece of paper that the patient has to actually sit here and read and check off all these boxes, and then, if she still wants those implants, power to her, that’s her decision as a patient. But we want them to have all that data readily available before making the decision.”
Agency officials also said they would no longer allow manufacturers to file summary reports that include dozens or more adverse events associated with breast implants or other medical devices that are less accessible than those filed in the public agency database called MAUDE (Manufacturer and User Facility Device Experience).
But Madris Tomes, a former program manager for the agency who founded a company called Device Events, said manufacturers could still use a new system of summary reporting put in place in August, called the Voluntary Malfunction Summary Reporting Program.
“I feel like this change is just semantics,” Ms. Tomes said. “What will keep manufacturers from duplicating their behavior and doing the same thing they were doing before, filing deaths and injuries in summaries so they aren’t viewable to the public?”
Raylene Hollrah, who was treated for the implant-associated lymphoma in 2013, said she was disappointed that the F.D.A. did not impose a ban.
She has become an advocate for patients, meeting with F.D.A. officials several times. At the hearing in March, she urged that the textured devices be removed from the market.
She praised the agency’s proposals to add warnings to implant labeling, and require doctors and patients to go over a checklist describing the risks.
Noting that the agency’s statement was not definitive, but used words like “would” and “could” for the actions proposed, Ms. Hollrah said, “It’s progress, but we are going to be watching closely. I can guarantee that we are here now and will be here in the future to make sure this is followed up. We’re not going away.”