Silicone breast implants and the risk of autoimmune/rheumatic disorders: a real-world analysis

Abstract
Objectives: Several epidemiological studies have investigated the link between silicone breast implants (SBIs) and autoimmune/rheumatic disorders, reporting inconsistent results. We aimed to evaluate the association between SBIs and the most clinically relevant autoimmune/rheumatic disorders using a large, population-based database. Methods: In this cross-sectional study, we used the computerized databases of Maccabi Healthcare Services (MHS), which include up to 20 years of data on 2 million members. Women with SBIs were identified by procedure and diagnosis codes, clinical breast examinations and mammography referrals. Autoimmune/rheumatic disorders were identified using the International Classification of Diseases 9th revision (ICD-9) codes. Multivariable logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). A Cox's proportional hazards model was used to calculate the hazard ratios (HRs) and 95% Cls among a subgroup of SBI recipients for whom the year of SBIs insertion was available. Results: We included 24 651 SBI recipients and 98 604 matched SBI-free women. The adjusted OR between SBIs and being diagnosed with any autoimmune/rheumatic disorders was 1.22 (95% CI 1.18-1.26). The strongest association with SBIs (OR > 1.5, p < 0.001) was recorded for Sjogren's syndrome, systemic sclerosis (SSc) and sarcoidosis (OR of 1.58, 1.63 and 1.98, respectively). Similar results were calculated when analysis was limited to women with no breast cancer history. A multivariable Cox regression model yielded a HR of 1.45 (95% Cl 1.21-1.73) for being diagnosed with at least one autoimmune/rheumatic disorder in women with SBI compared with those without. Conclusions: SBIs seem to be associated with higher likelihood of autoimmune/rheumatic disorders diagnosis.