RESUMO
BACKGROUND/AIM: The duration of pembrolizumab use in actual daily practice might be shorter than that in clinical trials because termination of pembrolizumab therapy is at the discretion of the physician. We retrospectively reviewed the response to pembrolizumab in Japanese patients with metastatic urothelial carcinoma (mUC) in relation to the time to response (TTR). PATIENTS AND METHODS: The records of 165 patients treated with pembrolizumab for mUC were retrospectively analyzed. Response was evaluated at 2, 4, 6 and 8 months. TTR along with time to best response were analyzed. Phase II-III clinical trials were also reviewed to compare the TTR and time to best overall response. RESULTS: The median patient age was 70 years. The objective response rate in the total cohort was 27.1% (42 out of 155 patients). Median TTR was 2.4 months and the time to best response was 3.1 months. Radiological evaluation at each time point significantly predicted overall survival (OS). Considering the evaluation of response at 2, 4, 6 and 8 months, the response at later time points tended to predict OS better. Multivariate analysis showed that the evaluation of response at 8 months (hazard ratio=1.91, 95% confidence interval=1.16-3.16 months; p<0.01) and best response during the treatment (hazard ratio=1.69, 95% confidence interval=1.17-2.44; p<0.01) independently predicted improved OS. CONCLUSION: Given that response when evaluated at a later point during pembrolizumab treatment more favorably reflected improved survival than when assessed earlier, physicians may be encouraged to wait until at least the termination of pembrolizumab treatment to determine the best response.
RESUMO
BACKGROUND/AIM: In clinical practice, platinum-based systemic chemotherapy works to shrink pelvic lymph nodes. Intra-arterial (IA) bolus infusion may result in more favorable results than systemic chemotherapy. In the present study, we investigated the distribution of cisplatin administrated by IA infusion in varying organs, specifically focusing on the node tissue, in comparison with the intravenous (IV) route. MATERIALS AND METHODS: Under anesthesia, cisplatin 0.42 mg/body was administrated by IA or IV infusion in rats to mimic a balloon-occluded arterial infusion model used in clinical practice. The kidney, bladder, lymphatic tissue, and peripheral blood were extracted to analyze the amount of cisplatin by inductively coupled plasma-mass spectrometry. RESULTS: Concertation of cisplatin by IA infusion was higher than that by the IV route in the peripheral blood and kidney. IA infusion led to a significantly high concentration of cisplatin in the bladder compared to IV infusion (1.3±0.452 vs. 0.2 ppb/mg ± 0.055, p=0.050). Furthermore, the IA method led to an extremely high concentration of cisplatin in the lymphatic tissue compared to the IV method (0.1±0.036 vs. 13.3±5.36, p=0.048). CONCLUSION: High cisplatin accumulation in the lymphatic tissue and bladder by IA administration may have a potential role for treating patients with node-positive bladder cancer.
