Advancing Surgical Strategies for Breast Cancer in the Era of Neoadjuvant Chemotherapy

Abstract

This thesis aimed to explore strategies to enhance surgical outcomes in patients receiving neoadjuvant chemotherapy (NACT). Paper I evaluated the effect of implementing surgical care bundles on postoperative surgical site infections (SSI) in a retrospective cohort (n=958). The results demonstrated that care bundle reduced the incidence of SSI by 2.9%, with a odds reduction of 37%. Paper II investigated the association of tumor-infiltrating lymphocytes (TILs) with tumor response and survival after NACT, in a retrospective cohort (n=220). Higher TILs were predictive of axillary tumor response following NACT. Although correlated with breast cancer-free interval, TILs showed no statistically significant correlation with overall survival. Paper III reported the interim results of a randomized trial of patients (n=44) with breast cancer undergoing NACT, comparing a novel one-stage magnetic technique for tumor localization with the conventional two-stage clip and guidewire approach. The results confirmed the feasibility of the new method, showing comparable outcomes in terms of resection volume ratio, negative margin rates and excellent safety profile. Paper IV evaluated a novel approach for pre-marking axillary lymph nodes by injecting superparamagnetic iron oxide nanoparticles (SPIO) before start of NACT (up to five months prior to surgery) with the standard technique of injecting a radioactive lymphatic tracer after NACT (one day prior to surgery), in a prospective cohort (n=80). The results demonstrated that SPIO performed better in detecting sentinel lymph nodes and almost half of them were different from those detected by radioactive tracer. In conclusion, collectively, these studies identify key opportunities to advance surgical practice by minimizing patient harm, personalizing axillary management based on predicted tumor response, and achieving greater precision in surgery after NACT.