Silicone-gel breast implants are safe and effective, the U.S. Food and Drug Administration declared Wednesday.

The agency also announced its future goal of including all stakeholders -- from implant manufacturer to women's health groups -- to improve the post-approval safety study of the breast implants. 

FDA continues to believe currently approved devices are safe and effective, said Dr. William Maisel, the deputy director for science and chief scientist for the Center for Devices and Radiological Health. He spoke at the end of a two-day advisory meeting of outside experts on post-market studies on silicone-gel breast implants funded by Allergan Inc. (AGN) and Mentor Worldwide LLC, the two implant makers.

After the two-day advisory panel discussion, Maisel said the FDA, along with the two companies and groups representing doctors and patients, wants to find ways to encourage study participation. Both Allergan and Mentor have agreed to assist FDA in successfully conducting long-term studies.

FDA halted the sales of silicone-gel implants in 1992 because of suspected links to autoimmune disease. But in November 2006, the agency approved silicone-gel implants manufactured by Mentor, a Johnson & Johnson unit, and Allergan. As a condition of approval, both the companies were required to continue studying their devices' performance for the next 10 years. 

The devices were recalled this year due to the failure of both the companies to follow up on thousands of women. In a two-day meeting with two FDA panels, both companies acknowledged their failure to keep track of women after implantation. According to FDA, Mentor has three-year data on only 21 percent of users and Allergan has data on 60.5 percent of women who were followed for only two years after implant.

It's unacceptable that many patients Mentor and Allergan were supposed to track were lost, said Jan Erickson of the National Organization for Women Foundation. Mentor's approval should be rescinded right away. And Allergan should be required to conduct further studies.

In a report released in June based on updated information, the FDA warned of a possible cancer link. The longer a woman has silicone gel-filled breast implants, the more likely she is to experience complications, the report further noted. According to FDA, 20 percent of the implants for breast augmentation will require additional surgery to remove, replace or fix the device while 50 percent of the implants used for reconstruction will need to be removed within 10 years.

Among side effects seen were capsular contracture, a hardening of the breast around the implant, infection, scarring, rupture and pain.