Pre-pembrolizumab neutrophil-to-lymphocyte ratio (NLR) predicts the efficacy of second-line pembrolizumab treatment in urothelial cancer regardless of the pre-chemo NLR

Neutrophil-to-lymphocyte ratio (NLR) was reported to be associated with prognosis of urothelial cancer (UC) patients receiving systemic chemotherapy or immunotherapy. However, it has not been elucidated how preceding first-line chemotherapy affects NLR and subsequent second-line pembrolizumab treatment. This multicenter study analyzed 458 patients with metastatic UC who received first-line chemotherapy and second-line pembrolizumab with regard to pre-chemotherapy and pre-pembrolizumab NLR in association with the efficacy of chemotherapy and pembrolizumab treatment. NLR was increased in 47% while decreased in 53% of patients before and after first-line chemotherapy. High pre-chemotherapy NLR (≥ 3) was significantly associated with unfavorable overall (OS, P = 0.0001) and progression-free (P < 0.0001) survivals after first-line chemotherapy. However, pre-chemotherapy NLR showed only modest influence on radiological response and survival after second-line pembrolizumab treatment, whereas pre-pembrolizumab NLR showed higher association. NLR decrease was associated with partial response or greater objective response by first-line chemotherapy, while NLR increase was associated with higher patient age. In conclusion, immediate pre-chemotherapy and pre-pembrolizumab NLR was significantly associated with efficacy of the following treatment, respectively. However, even patients with high pre-chemotherapy NLR achieved favorable OS if they had their NLR reduced by chemotherapy, whereas those with high pre-chemotherapy NLR yielded unfavorable OS if they had their NLR remained high after chemotherapy, suggesting that chemotherapy may have differential effect on the efficacy of subsequent pembrolizumab treatment in UC patients.