Question: How safe are silicone implants and are they better than saline implants for breast reconstruction?

Answer: Over 300,000 women undergo breast implant surgery for both augmentation and reconstruction in the United States each year. Clearly silicone implants are an invaluable reconstructive material for women who undergo disfiguring surgery for breast cancer.

Breast reconstruction at the time of mastectomy is being performed with increasing frequency as a part of the modern, multidisciplinary management of women with breast cancer. Most women do not have an alternative to implants if they choose reconstruction, and silicone gel-filled implants are superior to saline implants in their durability, feel and appearance. But silicone, as well as saline, implants may lead to problems, such as ruptures or hardening of the breast tissue around the implant.

The latest installment in the silicone gel-filled breast implant saga occurred in late July when the Food and Drug Administration said it would allow the sale of silicone implants manufactured by Mentor Corporation as long as the company met certain conditions. The announcement came three months after an FDA advisory panel recommended conditional approval. (Silicone implants made by another manufacturer, Inamed, were not approved by the advisory panel because of insufficient data.) Although the FDA cannot disclose the contents of the letter to Mentor, the company indicated the conditions are similar to those of the advisory panel, which included educating women about the chance of leakage, recommending regular MRIs (magnetic resonance imaging) to check for leaks, and new studies that prove how long the implants last.

The debate on the safety of silicone breast implants dates back to 1992 when the FDA placed a moratorium on their general use due to claims of serious health problems, including immune-related or connective tissue disorders, cancer and chronic fatigue, that were allegedly related to these devices. Exceptions to the restriction included breast reconstruction after a mastectomy, severe injuries, congenital malformations or to redo breast augmentation if the initial implant was silicone. Saline breast implants continued to be available for general use in women who wanted cosmetic breast augmentation, and in May 2000, the FDA gave its official approval of these devices.

During this period of controversy, more than 20 studies have been conducted to determine the safety of silicone implants, and none shows significant health hazards related to use. Most of these are retrospective studies that look backward, evaluating women who previously had various kinds of implants in different clinical settings. In contrast, more reliable prospective studies follow participants over a long period of time and watch for outcomes. Data are now becoming mature enough to provide evidence that silicone breast implants are safe and effective, but longer-term data are still needed. Data are also available from experience with silicone implants in Europe, where they have been available for more than 30 years for unrestricted use.

Since early detection is a key factor influencing breast cancer mortality, the effect of breast implants on screening has been examined closely. Fortunately, the utilization of special mammographic techniques and selected use of sonography and MRI examinations make successful screening possible in women with breast implants. Implants, when they are in the submuscular position, obscure about 10 percent of the breast tissue on specialized screening mammograms. The remaining breast tissue can be screened by physical exam. In fact, some studies show that more breast cancers may be detected by physical exam than by screening mammography in women with breast implants without cancer presenting at a more advanced stage.

Undoubtedly, there will be many more chapters to come in the implant story. As further research is conducted, more will be learned about the long-term effects of their use. Improved methods of production will increase their durability. Alternative materials are also being investigated to replace silicone gel, including natural oils and other compounds. As for the immediate future of silicone gel-filled implants, the ball is once again in the FDA’s court.

—Michael Grant, MD, breast surgeon, Baylor University Medical Center, Dallas