Silicone Gel Breast Implant Safety Remains Unclear

A new review of literature that examined health outcomes of silicone gel breast implants failed to provide clear evidence either for safety or harm.

Researchers at the University of Texas Southwestern Medical Center (Dallas, TX, USA) and Brown University (Providence, RI, USA) reviewed studies published through June 2015 to examine specific long-term health outcomes in women with silicone gel breast implants, including cancer development; connective tissue, rheumatologic, and autoimmune diseases; neurologic diseases; reproductive issues, including lactation; offspring issues; and mental health issues, included depression and suicide. In all, 32 longitudinal studies (in 58 publications) met eligibility criteria.

The researchers then extracted data on participant and implant characteristics that compared women with and without breast implants and reported long-term health outcomes of interest. The researchers found possible associations with decreased risk for primary breast and endometrial cancers and increased risks for lung cancer, rheumatoid arthritis, Sjögren syndrome, and Raynaud syndrome, but the evidence was frequently not specific to silicone gel implants, and studies were rarely adequately adjusted for potential confounders. The report was published on November 10, 2015, in Annals of Internal Medicine.

“Despite numerous studies reporting on the risk for many diseases and conditions, evidence was insufficient of an association between breast implants and any health outcome,” concluded lead author Ethan Balk, PhD, of the department of health services, policy, and practice at Brown University, and colleagues. “No outcome had at least two adequately adjusted studies that yielded consistent estimates of associations. There was a general lack of adequate accounting for possible confounders.”

“This project was conducted to provide background information for advice to be provided to the FDA regarding development of a silicone gel breast implant registry. While some databases may not have captured enough information, other studies might be worth reanalyzing to include more available confounders than before and with new methods,” added Dr. Balk. “We are hopeful that this study will serve as a guide to future researchers to improve analyses of currently available studies and of future studies.”

Silicone gel breast implants were removed from the US market for cosmetic use in 1992 owing to safety concerns. They were reintroduced in 2006, with a call for improved surveillance of clinical outcomes.

Related Links:
University of Texas Southwestern Medical Center
Brown University