The Impact of Neoadjuvant Chemotherapy on Implant-based Breast Reconstruction Outcomes

Neoadjuvant chemotherapy (NACT) is a critical component of breast cancer treatment, yet its impact on tissue expander (TE)-based breast reconstruction remains unclear. The purpose of this study was to examine the impact of NACT on complication rates after immediate TE-based breast reconstruction and on the commencement of adjuvant radiotherapy. Female patients who underwent immediate TE-based breast reconstruction between 2017 and 2022 were included. Inclusion criteria included patients who completed NACT within 2 months of mastectomy and those who did not receive chemotherapy. Patients who underwent bilateral prophylactic mastectomy, delayed reconstruction, adjuvant chemotherapy, and neoadjuvant radiation were excluded. A total of 2,013 patients were included, of whom 1,202 (59.7%) received NACT, and 811 (40.3%) did not receive chemotherapy. Rate of TE loss was significantly higher in the NACT cohort than the control cohort (9.8% versus 3.9%, p<0.001). Multivariable regression models showed that NACT significantly increases the rate of TE loss (OR=2.39, 95% CI: 1.47, 3.93, p<0.001) but no other complications, including cellulitis. NACT did not delay the commencement to radiation therapy. However, patients who developed cellulitis started radiation therapy on average 17 days later than those who did not (95% CI: 3.5, 31, p=0.014). NACT is a significant predictor of TE loss but does not prolong the commencement to radiotherapy. The increased rate of TE loss among the NACT group may reflect a higher rate of adjuvant radiation treatment and the combination of the deleterious effects of NACT and radiation therapy on wound healing.