The FDA issued the report Wednesday based on studies required by two U.S. companies that make implants, Allergan and Johnson and Johnson's Mentor unit. Industry critics pointed out the studies lack long-term follow-up with many of the women who took part in the studies, since many women tend to drop out. The FDA said it is working with the companies to increase study participation.
Though the agency concluded that silicone-gel implants are basically safe, they warned that women should understand they come with complications, including painful scar tissue and ruptured implants.
"The longer you have the implant, the more likely you are to have complications," said FDA medical device chief Jeff Shuren. He said women should get regular checkups including scans to make sure the implants haven't ruptured.
The research also showed a small link with a rare form of cancer known as anaplastic large cell lymphoma. The agency has learned of 60 cases of the disease worldwide, among the estimated 5 million to 10 million women with breast implants.
While the FDA's review focused on silicone-gel implants, the agency's updated advice booklet emphasizes that saline-filled implants also come with the same complications.
It's the FDA's first safety assessment since regulators returned silicone implants to market in 2006. The FDA had banned the silicone-gel type implants in 1992 amid fears they might cause cancer, lupus and other diseases. When research ruled out most of these concerns, regulators returned the implants with the requirement that manufacturers continue studying recipients.
Breast augmentation remains the most popular cosmetic surgery in the U.S., with nearly 300,000 women undergoing it last year. According to the American Society of Plastic Surgeons, more than 70,000 others received implants for breast reconstruction. Silicone-gel implants are the most common kind.
Based on that data, FDA said Wednesday that 20 percent to 40 percent of patients who have implants for cosmetic reasons will need another operation to modify or remove them within eight to 10 years.
Experts said the odds are even higher for cancer survivors. Reconstruction patients return to the operating room 40 to 70 percent within eight to 10 years.
This is because radiation for breast cancer damages the skin, making tissue stiffer over time. This means that the skin around the implants eventually appears tighter and higher on the chest as the tissue around it contracts. Also, women getting an implant after a mastectomy don't have a natural layer of breast tissue to cushion it.
The Associated Press contributed to this report.