The Food and Drug Administration (FDA) in the US has pushed back on a recent study that suggests that there is an association between silicone breast implants and some rare diseases, citing methodology problems.

The largest ever study of silicone breast implants was published on 14 September 2018 by researchers at the University of Texas MD Anderson Cancer Center in Houston. Data from nearly 100,000 women who had breast implants made by Johnson & Johnson and Allergan was considered. The women included in the study had either silicone-filled implants or saline-filled implants, which contain an outer silicone shell.

The analysis showed that those with silicone implants have a higher risk of certain diseases and complications such as rheumatoid arthritis, melanoma and stillbirth. It was not possible to say who was most at risk, but those conducting the study considered that it was important for physicians to be aware of the information so that if they do encounter one of the very rare occurrences, they can anticipate it and send patients for early evaluation and treatment.

The elevated risks for women with silicone implants included three conditions classified as autoimmune or rheumatologic disorders: Sjogren's syndrome, with a risk about eight times higher than in the general population; scleroderma, a seven-fold increase in risk; and rheumatoid arthritis, about a six-fold increase in risk. Silicone implants were also found to be associated with a 4.5-fold increase in the risk of stillbirth, but there was no significant increase in the risk of miscarriage. The chance of developing melanoma, a serious type of skin cancer, was nearly four times higher in women with silicone implants.

Compared to saline-filled implants, silicone implants were also linked to a higher risk of some surgical complications, including capsular contracture (scarring around the implant), which occurred at a rate of five per cent with silicone implants versus 2.8 per cent with saline-filled implants. Capsular contracture occurred in 7.2 per cent of primary breast augmentation procedures, and was the most common reason for revision surgery.

Elise Bevan, a solicitor in the clinical negligence team at Penningtons Manches who specialises in cosmetic surgery claims, commented: “While this study has sparked controversy within the medical community and caused concern for women who have had silicone breast implants, the advice from the FDA is that the results should be reviewed with caution. Firstly, there is no proven direct link or causative effect between the implants and the reported conditions, but rather an association. Secondly, whilst certain conditions appeared to be more common in women with silicone implants, absolute rates of these adverse outcomes were low. Further, both the FDA officials and the study authors have pointed out that there were several limitations to the study, with both groups analysing the same information but coming to different conclusions.

“The FDA is not, however, dismissing the findings and has called a meeting next year to review all available data, including the results of this study. In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) continues to review adverse event reports and current literature to build a more accurate picture of potential problems related to breast implants.