Surgical outcomes following neoadjuvant chemotherapy with and without immunotherapy in patients with triple-negative breast cancer

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 Fisher's 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.