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

Abstract

Background: 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, the authors investigated the effect of breast reconstruction with macro-textured SBIs on long-term oncologic outcomes of breast cancer patients.

Materials and methods: The authors conducted a retrospective cohort study in two large cancer centres in the Netherlands. Patients who had been treated for primary breast cancer between 1 January 2000 and 31 December 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 were accounted for by multiple imputations 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.

Results: Of the 4695 women who were eligible for inclusion, 2393 had undergone mastectomy. Of these women, 1187 (25%) had received breast reconstruction with a macro-textured SBI. The 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 various subgroup analyses yielded similar results.

Conclusion: 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.

Figure 1

Flow diagram of included patients and analyses. BCS, breast-conserving surgery; FU, follow-up; IBBR, implant-based breast reconstruction; MICE, multiple imputation by chained equations.

Figure 2

Sensitivity analysis and subgroup analyses at a glance: Locoregional recurrence-free survival, distant metastasis-free survival and overall survival in patients with implant-based reconstruction versus patients who underwent mastectomy without consecutive implant-based reconstruction. (A) Sensitivity analysis in complete cases. (B) Subgroup analyses in (B1) patients over the age of 50 at diagnosis and (B2) patients 40 years or younger at diagnosis. (C) Subgroup analyses according to hormone-receptor status. (C1) Oestrogen-receptor positive breast cancer, (C2) human epidermal growth factor receptor 2 (HER2) positive breast cancer, and (C3) triple-negative breast cancer. (D) Subgroup analyses according to breast cancer stage. (D1) Stage I, (D2) Stage II, and (D3) Stage III. For detailed descriptions of sensitivity analysis and subgroup analyses please see Table 3, Supplement B, Supplemental Digital Content 2, http://links.lww.com/JS9/C888 and Supplement C, Supplemental Digital Content 3, http://links.lww.com/JS9/C889.