Association of Neoadjuvant Versus Adjuvant Chemotherapy on Pre-Pectoral Tissue Expander Based Reconstruction Outcomes Following Mastectomy

Background: Prepectoral implant-based reconstruction has reemerged as a preferred technique for breast reconstruction after mastectomy, but introduces risks of prothesis infection. With increasing reliance on neoadjuvant chemotherapy (NACT), which can modulate the immune system and induce leukopenia, it is unclear how NACT impacts surgical outcomes in prepectoral reconstruction patients. This retrospective review aims to investigate the impact of NACT and leukopenia on complication rates in patients undergoing immediate pre-pectoral TE-based breast reconstruction compared to adjuvant chemotherapy or no chemotherapy. Methods: A single-center retrospective review evaluated surgical outcomes in all two-stage immediate prepectoral breast reconstruction patients between January 2018 and September 2022. Patients were stratified by treatment type (NACT, ACT, or none) and the presence of leukopenia was delineated. Complication rates between groups were analyzed with univariate comparisons and a multivariate mixed effects logistic regression was run for major complications. Results: Of the 295 patients analyzed, those with NACT experienced fewer major complications compared to the ACT or no chemotherapy cohorts (14.1% vs 41.8% vs 28.5%, p = 0.0012) following TE placement. There were no significant differences in individual complications or outcomes following implant exchange. Patients with perioperative leukopenia experienced lower major infections rates, but higher hematoma rates following TE placement (p<0.05). Following implant exchange, they experienced lower explantation rates but higher reoperation and skin necrosis rates (p<0.05). Conclusion: This study demonstrates that ACT is associated with higher risks of major complications after prepectoral tissue expander placement in our cohort, but that NACT and perioperative leukopenia were not predictors of complications compared to no chemotherapy.