Prognostic value of the fluctuation in the neutrophil-lymphocyte ratio at 6 weeks of pembrolizumab treatment is specific to the clinical response in metastatic urothelial carcinoma.

ABSTRACT

PURPOSE: Most patients with metastatic urothelial carcinoma experience no objective response to pembrolizumab and have poor overall survival (OS). Here, we investigated the prognostic value of fluctuation in the neutrophil-lymphocyte ratio (NLR) at 6 weeks of pembrolizumab treatment, focusing on its association with the achievement of objective response. MATERIALS AND METHODS: The clinical records of 177 metastatic urothelial carcinoma patients treated with pembrolizumab were retrospectively analyzed. RESULTS: The median age was 72 years, and the median OS was 14 months. The objective response rate in the total cohort was 26.5% (47 of 177 patients). Multivariable analysis showed that objective response achievement (hazard ratio 0.3 [95% confidence interval 0.15-0.59], P < 0.001) and decline in NLR from that at baseline at 6 weeks of treatment (0.54 [0.34-0.88], P = 0.013) were independent prognostic factors for improved OS. For 47 (26.5%) patients who achieved an objective response, OS was similar regardless of NLR fluctuation at 6 weeks of treatment (P = 0.723). Intriguingly, of the 130 (73.5%) patients with no objective response, those who showed a decreased NLR at 6 weeks of pembrolizumab treatment (57 patients) from that at baseline had significantly longer OS than those with elevated NLR (73 patients) (14 vs. 6 months, P = 0.007). CONCLUSIONS: The fluctuation in NLR from that at baseline at 6 weeks of pembrolizumab treatment may be useful for patients without an objective response. This could potentially aid decision-making for post pembrolizumab therapies.