Impact of neoadjuvant chemo-immunotherapy on surgical outcomes and time to radiation in triple negative breast cancer.

Abstract

555 Background: The impact of preoperative chemo-immunotherapy on surgical complications and timing of adjuvant therapy is not well understood. We examined the association between neoadjuvant pembrolizumab plus chemotherapy (NAC+P) compared to neoadjuvant chemotherapy alone (NAC) and treatment delays and postoperative complications in triple negative breast cancer (TNBC). The effect of immune-related adverse events (irAEs) on these outcomes was also compared. Methods: 143 women with stage II-III TNBC treated with NAC+P based on the KEYNOTE 522 (KN522) regimen from 8/2021-9/2022 were compared to 287 consecutive patients who received NAC prior to 7/2021. Baseline characteristics, time to treatments, and surgical complications were compared between KN522 and non-KN522, and among KN522 with/without irAEs using two-sample non-parametric tests. Linear regression evaluated association of irAEs with time to surgery and radiation. Conditional logistic regression identified factors associated with surgical complications among KN522 patients. Results: Age, BMI, race, ASA class, and mastectomy rates were similar among KN522 and non-KN522 patients. Interval from end of neoadjuvant treatment until surgery was one day longer for patients receiving NAC+P (median 32 days (IQR 27, 43) vs. 31 days (26, 37) non-KN522, p = 0.035). Time to radiation did not differ (p = 0.2). Postoperative complications occurred in 26 (9%) non-KN522 vs 12 (8.4%) of KN522 patients (p = 0.7) (Table). 55/144 (38%) of KN522 patients experienced 74 irAE; 42 (76%) required treatment. Pembrolizumab was held in 21 (38%) and discontinued permanently in 17 (31%). One KN522 patient experienced a fatal irAE (pneumonitis). Older age (coeff. 0.38, 95% CI 0.06-0.70, p = 0.02) and ASA class 4 (coeff. 53, 95% CI 14-92, p = 0.009) were associated with delays to surgery but irAE was not (p = 0.070). Neither presence of irAE (coeff. 6.8, 95% CI -0.74-14, p = 0.081) or number of irAEs (coeff. 4.1, 95% CI -1.2-9.3, p = 0.13) were associated with time to radiation. IrAEs were not associated with surgical complications (p = 0.5). Conclusions: Postoperative complications or delays to surgery or adjuvant radiation were similar in patients treated with NAC+P compared to NAC. IrAEs were not associated with delays to surgery or adjuvant radiation or postoperative complications. [Table: see text]