By Lisa Rapaport

(Reuters Health) – Women with silicone breast implants may have a higher risk of certain medical problems than women who don’t get implants, but more research is needed to get a complete picture of implant safety over the long term, a new U.S. study suggests.

The U.S. Food and Drug Administration (FDA) banned silicone breast implants in 1992 over concerns about an increased risk of cancer, connective tissue diseases and autoimmune disorders that were disproved by subsequent research. As a condition of approving a new generation of silicone implants in 2006, the FDA required manufacturers to gather long-term safety information.

For the current analysis, researchers examined data from almost 100,000 women who had breast augmentation or reconstruction with either the new generation of silicone implants or with saline alternatives. Women were followed from two to seven years, although most were studied for no more than three years.

“Breast implants were found to have common complications such as infection, scar development, rupture, and the need for re-operation,” said senior author Dr. Mark Clemens of the University of Texas MD Anderson Cancer Center in Houston.

“We also found that silicone implants were very rarely associated with some diseases, and these findings were confirmatory and in line with previous smaller studies on breast implants,” Clemens said by email.

Over the short term, women had a higher likelihood of an implant rupturing with the saline versions. This happened in 2.5 percent of women with saline implants and in 0.5 percent of women with silicone, researchers report in the Annals of Surgery.

Compared to women without implants, however, women with silicone implants had an eight times higher risk of Sjogren’s syndrome, a rare immune system disorder characterized by dryness in the eyes and mouth that is often accompanied by other immune problems like arthritis or lupus.

With silicone implants, women also had seven times the risk of scleroderma, a different rare immune system disorder that leads to hardening and tightening of the skin and connective tissue.

Silicone implants were also associated with almost six times the risk of rheumatoid arthritis, an inflammatory joint disorder.

The study did not find comparable risk increases for saline implants but did not directly compare silicone and saline implants.

While the data were gathered to detect safety issues with new-generation silicone implants, the current study was not a controlled experiment designed to compare various silicone implants to one another, the authors note. The researchers also lacked detailed data on individual patients and could only assess results for large groups of women.

Previous research has found an increased risk of certain cancers associated with textured breast implants, but the current analysis lacked data on this aspect of implants and could not examine how other aspects of the implants or procedures to place them might have influenced safety outcomes for women.

“Given the study design’s limitations, it would not be appropriate to warn patients about a higher risk of connective tissue or autoimmune disorders,” with silicone implants, said Dr. Michael Alperovich of Yale University School of Medicine in New Haven, Connecticut.

“The study does support performing a more rigorous, methodologically sound analysis to better explore the identified associations,” Aperovich, who wasn’t involved in the study, said by email.

Based on the currently available data, both silicone and saline appear safe, said Dr. Tomer Avraham, also of Yale.

“This issue, however, is not settled with 100 percent certainty, and all types of surgery is associated with risks,” Avraham, who wasn’t involved in the study, said by email. “Therefore, vigilance is warranted.”

SOURCE: Annals of Surgery, online September 14, 2018.