[CLINICAL EVALUATION OF THERAPEUTIC EFFECT PREDICTORS IN PEMBROLIZUMAB FOR ADVANCED UROTHELIAL CANCER].

(Purpose) We performed a clinical retrospective study on the evaluation of pembrolizumab treatment results for advanced urothelial cancer in our hospital. (Materials and Methods) Twenty-seven patients diagnosed with advanced or metastatic urothelial carcinoma who received pembrolizumab between April 2018 and December 2021 were included. We retrospectively reviewed medical records to examine treatment outcomes, immune-related adverse event (irAE), and prognostic factors. (Results) The median age of patients was 76 years, and the median number of pembrolizumab doses was 6. The median overall survival was 8.8 months, and the best treatment response according to RECIST version 1.1 was complete response 1, partial response 7, stable disease 5, and progression disease 14. Pre-pembrolizumab risk factors related to overall survival include the presence of liver metastasis, LDH ≥200 IU/L, and TSH <4 μIU/mL in univariate analysis. Grade 3 irAE was type 1 diabetes in only 1 case, and grade 2 were hypothyroidism in 4 cases, type 1 diabetes in 1 case, interstitial pneumonia in 1 case, and skin disorder in 1 case. Nine patients had a TSH of 4 μIU/mL or higher at the start of pembrolizumab, and four of them had hypothyroidism requiring oral levothyroxine, and none of the patients in the low TSH group required hormone replacement (p =0.013). (Conclusion) High TSH level before pembrolizumab administration for advanced urothelial cancer was associated with hypothyroidism, suggesting the possibility of improved prognosis.