Optimal breast reconstruction type for patients treated with neoadjuvant chemotherapy, mastectomy followed by radiation therapy.

[PURPOSE] To explore the optimal type of breast reconstruction and the time interval to postmastectomy radiotherapy (PMRT) associated with lower complications in breast cancer patients receiving neoadjuvant chemotherapy.

[METHODS] We reviewed the medical records of 300 patients who received neoadjuvant chemotherapy, mastectomy with breast reconstruction and PMRT at our institution from 2000 to 2017. Reconstruction types included autologous flaps (AR), single-stage-direct-to-implant and two-stages expander/implant (TE/I). The primary endpoint was the rate of reconstruction complications including infection, skin and fat necrosis. Subgroup analysis compared rates of capsular contracture, implant rupture, implant exposure and overall implant failure in single-stage-direct-to-implant to TE/I. The secondary endpoint was identifying the time interval between surgery with immediate implant-based reconstruction and PMRT associated with lower probability of implant failure. Logistic regression models, Kaplan-Meier estimates and Polynomial regression were used to assess endpoints.

[RESULTS] The median follow-up was 43.5 months. 29.3%, 28.3% and 42.4% of the cohort had AR, TE/I and single-stage-direct-to-implant D, respectively. The 5-year cumulative incidence rate of complications was 14.0%, 29.7% and 19.4% for AR, TE/I and single-stage-direct-to-implant, respectively (Log rank p = 0.02). Multivariate analysis showed significant association between TE/I and higher risk of infection (OR 8.1, p = 0.009) compared to AR, while single-stage-direct-to-implant and AR were comparable (OR 3.2, p = 0.2). On subgroup analysis, TE/I was significantly associated with higher rates of implant failure. The mean wait time to deliver PMRT after immediate reconstruction with no adjuvant chemotherapy was 8.4 and 10.7 weeks in single-stage-direct-to-implant and TE/I, respectively (p < 0.005). Delivering PMRT after 8 weeks of surgery yielded 10% probability of reconstruction failure in single-stage-direct-to-implant versus 40% in TE/I.

[CONCLUSION] In comparison to two stages reconstruction, single-stage-direct-to-implant following neoadjuvant chemotherapy has lower complications and offers timely delivery of PMRT.