A public interest group called Thursday for a criminal investigation into a whistleblower's allegations that a silicone-breast implant maker withheld safety information from U.S. regulators.

The U.S. Food and Drug Administration said it already had investigated the charges and had found no evidence of wrongdoing.

About 15 per cent of women in Canada seeking breast implants receive the silicone type.
(CBC)

The agency is considering Mentor Corp.'s application to sell the implants.

In a letter to the FDA, Public Citizen said a former Mentor employee had alleged that the Santa Barbara, Calif., company concealed, misrepresented or withheld leakage, durability and other data about its silicone-gel breast implants.

"Unless the FDA opens a criminal investigation into Mentor's failure to submit the studies, it will only encourage Mentor and other device manufacturers to selectively send the agency only those studies that put their products in the most favourable light," said Dr. Sidney Wolfe, director of Public Citizen's Health Research Group.

FDA spokeswoman Heidi Valetkevitch responded, "The agency conducted a thorough investigation into these charges and found no evidence of wrongdoing and nothing that would raise questions about the safety of the product under review or the integrity of the data submitted to FDA."

In a statement, Mentor said FDA representatives visited the company's Santa Barbara facilities in July. "To our knowledge, all questions were answered to the satisfaction of FDA," the company said.

In July and September 2005, the FDA first told Mentor and then Inamed Corp. — now part of Allergan Inc. — that it would allow them to sell silicone implants once certain unspecified conditions had been met.

The FDA has yet to grant final marketing approval to either competitor. Since a de facto 1992 ban in the U.S., silicone implants have been used in women only as part of clinical trials.

Whistleblower concerns

The former employee first raised his concerns with Mentor last year. He was laid off in May and a month later contacted FDA officials.

In a telephone interview, the whistleblower said the FDA eventually told him that both companies had satisfied the requirements spelled out in agency guidelines and that "no further open items would be reviewed."

The scientist spoke to the Associated Press on condition of anonymity to avoid jeopardizing ongoing efforts to find work.

Wolfe did not identify the scientist but said he had confirmed he had worked for Mentor.

The scientist is the latest of several Mentor whistleblowers to raise concerns about the company's silicone breast implants.

Silicone-gel breast implants first went on the market in 1962, before the FDA required proof that all medical devices be safe and effective. They were banned in the U.S. 1992 amid concerns about their safety. At the time, women worried they were the cause of a variety of diseases, including cancer. Alarming cases of ruptures contributed to the concern.

In Canada, the government asked for a voluntary moratorium on the sale of silicone implants. About 15 per cent of women receiving implants still ask for and receive the silicone type.

Most studies have failed to find a link between breast implants and disease. But silicone-gel breast implants do not last a lifetime, according to the FDA. A 2000 Institute of Medicine report found rupture rates as high as 77 per cent.

Proponents of silicone-gel implants say they feel more natural than saline implants.