Predictive roles of NETs and IgG in neoadjuvant chemotherapy for muscle-invasive bladder cancer.

Abstract

659 Background: Cisplatin-based chemotherapy is the recommended therapy for muscle-invasive bladder cancer (MIBC), in the neoadjuvant setting. However, the efficacy of MIBC for chemotherapy is only about 40%. Therefore, predictors of therapy response are urgently needed. Neutrophils form neutrophil extracellular traps (NETs), a network structure, and growing evidence indicated that it could be a prognostic and predictive marker in cancer. Besides, NETs and IgG could reflect the immune response, even may induce immune tolerance. In MIBC, the predictive role of NETs or IgG in chemotherapy resistance is unclear. Methods: This study included 54 patients with MIBC undergoing neoadjuvant chemotherapy. Immunohistochemical staining with NETs was performed on tumor primary lesions before chemotherapy, and the staining intensity was scored. Serum IgG levels in the pre-treatment baseline and 1 month after chemotherapy were also measured for these patients. Results: Citrullinated histone H3 (H3Cit) as a hallmark of NETs, was an independent predictor of chemotherapy resistance as determined by the multivariate logistic regression analyses [OR=5.94, 95% CI 1.20–45.50, P=0.045]. Additionally, in patients with favorable chemotherapy response, serum IgG levels significantly decreased after 1 month of treatment (P=0.0018), while in those with poor response, there was no significant change. Conclusions: The baseline levels of NETs and the change of IgG after 1-month treatment demonstrated predictive capabilities during neoadjuvant chemotherapy, possibly reflecting the immune status. MIBC patients with high NETs and IgG levels were resistant to neoadjuvant chemotherapy, providing new insights into the treatment of MIBC. However, these results require further validation through larger sample studies. Further validation of our findings could provide a theoretical basis regarding NETs inhibitors or IgG antibodies combined with chemotherapy strategy.