Nine women are believed to have died in the United States from a rare cancer linked to breast implants, US health officials said Tuesday, with more than 350 cases of the disease recorded nationwide.
A possible association between breast implants and anaplastic large-cell lymphoma (ALCL) was first identified in 2011 but at the time few cases had been recorded.
Now the US Food and Drug Administration says it has received 359 reports of ALCL linked to implants, including nine fatalities.
"All of the information to date suggests that women with breast implants have a very low but increased risk of developing ALCL compared to women who do not have breast implants," said the FDA release.
The health agency said it concurred with the World Health Organization, which has designated breast-implant associated ALCL "as a rare T-cell lymphoma that can develop following breast implants."
Most confirmed cases have occurred in women with textured breast implants as opposed to smooth-surfaced ones, the FDA said.
It also pointed out that the rare condition had been most frequently identified in women "undergoing implant revision operations for late onset, persistent seroma" - a build-up of fluid under the skin.
The type of implant filler appeared to make less difference, with 186 of the medical reports recording breasts filled with silicone gel and 126 recording saline filler. The rest did not specify.
The FDA said the exact number of cases remained difficult to calculate owing to limitations in global reporting and implant sales data.
Most cases have been treated by removing the implant but some women have required chemotherapy and radiation, it said.
In December, Australia's Therapeutic Goods Administration reported 46 confirmed cases of breast implant-associated ALCL in the country, including three deaths.
France's national cancer institute warned two years ago that there was a "clearly established link" between ALCL and silicone implants, noting 18 cases since 2011.
Given the rarity of the cases, the institute said there was no need to recommend the removal of the implants.