Ongoing Safety Studies Have Lost as Many as 79% of Enrolled Patients
By Brenda Goodman
WebMD Health News
Reviewed by Michael W. Smith, MD
Aug. 30, 2011 -- A panel of expert advisors to the FDA has been asked to solve a mystery: What happened to thousands of women who enrolled in studies designed to evaluate rare complications that might arise years after they received silicone gel breast implants?
In June, after a preliminary review of study data, the FDA concluded that breast implants were largely safe and effective but were not "lifetime devices," citing high reoperation rates for complications like hardening of the breast and rupture of the implant.
That review also found no evidence that silicone implants were linked to rare problems like breast cancer or connective tissue diseases, concerns that have plagued the devices for decades. But the agency also noted that studies were still in progress to better answer some of those questions about rare events.
Now, however, it seems those studies have lost so many of the women they were supposed to follow that they are unlikely to offer any insight into the long-term safety of the devices.
Breast Implant Studies in Trouble
When the FDA allowed silicone gel breast implants back on the market in 2006, a condition of that approval was that companies conduct additional clinical trials to monitor complication rates and other problems that might develop over the long-term.
Some of the potential rare events that the FDA and patient advocacy groups wanted continued monitoring for included connective tissue diseases like lupus, rheumatoid arthritis, and scleroderma; nerve problems; cancer; suicide; interference with mammograms; problems in babies born to women with breast implants; and women with implants who might have had trouble getting pregnant or breastfeeding.
The companies agreed, and studies were designed that enrolled more than 82,000 women with silicone breast implants and 16,000 women with saline implants for comparison. The studies were supposed to follow the women for 10 years.
But three years into the studies, Mentor, the maker of Memory Gel implants, has lost 79% of the patients they enrolled, while Allergan, the maker of Natrelle implants, has lost nearly 40% of their study participants two years after enrollment.
As a result, experts said the studies had already lost the power to detect the rare events they were designed to look for.
"Based on these study designs, it's not going to be more powerful to just double the length of time the studies are running," said Phil Haeck, MD, president of the American Society of Plastic Surgeons, who attended the hearing.
It is the panel's task in the two-day meeting to help the FDA find a way to "fix the current dilemma," Haeck said.
Charged with that task, the panel listened on Tuesday to testimony from the FDA, device manufacturers, women with breast implants, and doctors about how design better safety studies for breast implants.
Manufacturers Say Safety Is a Top Priority
"Mentor's top priority has been and always will be patient safety," said John Canady, MD, medical director of Mentor Worldwide in testimony to the General and Plastic Surgery Devices Advisory Panel to the FDA.
"The current large, post-approval study, unfortunately, though, has not given us the additional data that we hoped for, but I can assure you that plastic surgeons have tried hard in this effort."
Mentor said it had worked with the FDA to send letters to participating patient and doctors enrolled in the study to stress the importance of their participation and that the company had made some changes to its study web site to make it easier to use.
Canady said the major reason many women were lost was that most women who get their implants feel fine after their surgeries and that "patients who feel well just don't go to the doctor."
Other company representatives testified that the requirements of the studies, which include regular return trips to their plastic surgeon, filling out an annual, 27-page questionnaire, and recommended MRI scans to check for silent rupture -- which patients have to pay for at up to $2,000 a scan -- were simply too burdensome for doctors and patients.
The company asked the panel to consider letting them use other sources of data, including case reports and patient registries, to meet the requirements.
Patients, Advocates Say Important Questions Haven't Been Answered
But patients and advocates took issue with many of those arguments.
Sidney M. Wolfe, MD, director of the Health Research Group at the nonprofit Public Citizen in Washington, D.C., says women are also less likely to return to a doctor or study when they've experienced a bad outcome, which means the studies may be missing important safety problems.
"The flip side is that people who are enraged at their plastic surgeon who didn't bother telling them that these would have to be replaced in four, five, or six years go to someone else, so it works both ways," Wolfe says.
By the end of the day, panel experts seemed unconvinced that the companies were doing enough to follow up with patients.
Jason T. Connor, PhD, a statistical scientist with Berry Consulting in Orlando, Fla., who was a temporary voting member of the advisory panel, noted that it was in the company's best interest not to look too hard for safety problems with their products.
"We're running really large 40,000-patient studies that tell us nothing because the companies aren't incentivized to get the results we really care about," said Connor.
The hearing will continue on Wednesday.
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