Recurrence of breast cancer after reconstruction with macro-textured silicone breast implants: A retrospective cohort study.

Abstract

Recently, old concerns linking silicone breast implants (SBIs) with breast cancer have resurfaced. These concerns apply specifically to the risk of breast cancer recurrence in patients who received breast reconstructions with macro-textured SBIs. In this study, we investigated the effect of breast reconstruction with macro-textured SBIs on long-term oncologic outcomes of breast cancer patients. We conducted a retrospective cohort study in two large cancer centres in the Netherlands. Patients who had been treated for primary breast cancer between January 1st 2000 and December 31st 2015 were included. Data on treatment and oncologic outcomes were obtained from prospectively maintained institutional and nationwide registries. Patient files were reviewed manually to complement missing information. Missing data was accounted for by multiple imputation by chained equations (MICE). Reconstruction with a macro-textured SBI was analysed as a time-dependent variable. The main outcomes of interest were locoregional recurrence-free survival (LRRFS) and distant metastasis-free survival (DMFS). Hazard Ratios (HRs) were estimated using multivariable Cox proportional hazard models. Of the 4,695 women who were eligible for inclusion, 2,393 had undergone mastectomy. Of these women, 1,187 (25%) had received breast reconstruction with a macro-textured SBI. Mean follow-up time was 11.5 (SD, 5.0) years. Compared with women who had undergone a simple mastectomy or autologous breast reconstruction, women with an implant-based reconstruction did not differ significantly in LRRFS or DMFS after accounting for various confounding factors (HR 1.27 [95% CI 0.93 - 1.72] and HR 0.94 [95% CI 0.74 - 1.20], respectively). Sensitivity analysis in complete cases of patients and varies subgroup analyses yielded similar results. Reassuringly, in this multi-centre cohort study no difference was found in long-term oncologic outcomes between women who had received breast reconstruction with a macro-textured SBI and women who had undergone a simple mastectomy or autologous breast reconstruction.