%0 Journal Article %A IKKO TOMISAKI %A MIRII HARADA %A KEI TOKUTSU %A AKINORI MINATO %A YUJIRO NAGATA %A RIEKO KIMURO %A MASAHIRO MATSUMOTO %A NAOHIRO FUJIMOTO %T Impact of C-reactive Protein Flare Response in Patients With Advanced Urothelial Carcinoma Who Received Pembrolizumab %D 2021 %R 10.21873/invivo.12659 %J In Vivo %P 3563-3568 %V 35 %N 6 %X Background/Aim: To clarify the clinical significance of the temporary elevated C-reactive protein (CRP) levels followed by a decrease below baseline (CRP flare response) after administration of pembrolizumab to patients with advanced urothelial carcinoma (UC). Patients and Methods: We retrospectively reviewed 31 patients with advanced UC who received pembrolizumab. Patients were categorized into 3 groups (flare-responder, responder, non-responder) according to early CRP kinetics. Intergroup tumor response and survivals were compared. Results: Objective response rates of flare-responder, responder, and non-responder groups were 75%, 80%, and 26%, respectively. Median overall survival was not reached in flare-responder and responder groups, and was 10.2 months in the non-responder group (p=0.03). Furthermore, the flare-responder group did not reach median progression-free survival, and for the responder and non-responder groups it was 15.2 and 2.8 months, respectively (p=0.03). Conclusion: CRP flare response might be a promising biomarker in patients with advanced UC who received pembrolizumab. %U https://iv.iiarjournals.org/content/invivo/35/6/3563.full.pdf