UCLA

PURPOSE: Adding pembrolizumab to neoadjuvant chemotherapy (NAC) for triple-negative breast cancer (TNBC) improves pathologic complete response (pCR) rates and event-free survival. The impact of adding immunotherapy to NAC on surgical outcomes is unknown. This study compares 90-day post-surgical complications (PSCs) and time to adjuvant treatment among patients undergoing NAC for TNBC with and without immunotherapy. METHODS: Patients treated with NAC alone or with immunotherapy (NAC-I) for stage I-III TNBC between 2018 and 2022 were retrospectively identified at a single academic institution. Kruskal-Wallis rank sum and Fishers exact tests compared patient sociodemographic and clinical characteristics. Multivariable logistic regression determined odds ratios (OR) predicting PSCs. RESULTS: Of 54 patients, 29 received NAC alone and 25 received NAC-I. Compared to NAC patients, NAC-I patients had more advanced stage tumors (p = 0.038), and had slightly higher rates of mastectomy with reconstruction (p = 0.193). 72.0% of NAC-I patients experienced a pCR, compared with 44.8% of NAC patients (p = 0.193). There were 10 PSCs (34.5%) in NAC patients compared to 9 PSCs (36.0%) in NAC-I patients (p > 0.99). Regression analysis demonstrated no association of PSCs with NAC-I (OR 0.83, 95% CI 0.19-3.60). Time to adjuvant therapy was shorter for NAC-I patients (28 days vs 36 days, p = 0.013). CONCLUSIONS: Patients with TNBC receiving NAC-I have higher pCR rates and do not appear to have added 90-day PSCs or delays to adjuvant therapy despite trending toward more extensive surgical procedures compared to NAC alone. Larger studies are needed to further evaluate the surgical safety of immunotherapy.