Autoimmune conditions and ‘breast implant illness’ in breast cancer patients with implant-based breast reconstructions.

Abstract

12035 Background: The safety of silicone breast implants (SBIs) has been challenged in various large observational studies that suggest an association with autoimmune and rheumatic diseases (ARDs). Additionally, an increasing number of women seem to attribute constitutional, rheumatic, mental and cognitive symptoms to their SBIs. This constellation of symptoms is often referred to as ‘Breast implant illness (BII). To date, BII is a self-identified diagnosis without an evidence-based definition. The risks of ARDs and BII have not been evaluated in breast cancer survivors with implant-based breast reconstructions. Methods: We conducted a retrospective cohort study among patients treated for breast cancer between 2000 and 2015 in six large regional hospitals. Clinical data and diagnoses of ARDs were obtained up to 2023 from prospectively maintained institutional and nationwide registries. Patients who were alive at the time of study were invited to participate in a survey. The occurrence of eighteen symptoms, that have been associated with BII by international experts, was assessed. The SBI-exposed patients were compared with patients who had received other surgical treatment modalities. In the entire cohort (including deceased patients and survey non-responders), Hazard Ratios (HRs) for receiving an ARD diagnosis were estimated through multivariable Cox models. Among responders to the survey, person-centered symptom clusters were determined through a latent class analysis approach. The association between SBI-exposure and the observed symptom clusters was analyzed in multivariable logistic regression models. Results: Of 12,262 women in the entire cohort, 3,082 (25%) had received a SBI-based breast reconstruction. Median follow-up time was 12.0 (IQR, 7.0) years. Compared with non-exposed patients, patients with an implant-based breast reconstruction did not have an increased risk of ARDs in general (HR, 1.06, 95% CI [0.89–1.27]) or any specific ARD-category or specific condition. In total, 6,073 patients (64.5% of all invited patients) completed the questionnaire including 1,818 patients with an SBI. In the survey cohort, the median follow-up time was 13.7 (IQR, 6.8) years. Five distinct BII-related symptom clusters were identified, none of which were significantly associated with SBI-exposure in multivariable logistic regression analyses. Additionally, when comparing exposed to non-exposed women, women with SBIs did not have a significantly increased risk for any of the individual BII-associated symptoms. Conclusions: Our results indicate that breast cancer patients with SBIs do not have an increased risk of ARDs nor do they experience more BII-associated symptoms compared with breast cancer patients without SBIs. This information can aid healthcare professionals in counseling breast cancer patients who are worried about the alleged long-term harms of SBI(s).