Impact of inflammatory marker levels one month after the first-line targeted therapy initiation on progression-free survival prediction in patients with metastatic clear cell renal cell carcinoma

Objectives: Progression-free survival of first-line targeted therapy greatly influences the survival of patients with metastatic renal cell carcinoma. We evaluated whether post-treatment inflammatory markers and lactate dehydrogenase levels had impacts on progression-free survival prediction in addition to those of conventional predictors. Methods: Two hundred and fifteen patients whose tumors were clear cell type and in whom first-line targeted therapies could be continued for >1 month were evaluated. Pretreatment clinical factors, pathological factors and laboratory data 1 month after targeted therapy initiation-including inflammatory markers (neutrophil count, neutrophil-to-lymphocyte ratio and C-reactive protein) and lactate dehydrogenase-were reviewed. To identify progression-free survival predictors, multivariate analyses were done. Results: The 1-year progression-free survival rate was 47%. Female gender, Karnofsky performance status <80%, time from diagnosis to systemic treatment <12 months, pretreatment C-reactive protein >3.0 mg/dl and post-treatment neutrophil-to-lymphocyte ratio >3.0 were independent predictors for progression-free survival. In contrast, neither C-reactive protein increase nor neutrophil-to-lymphocyte ratio increase after targeted therapy initiation were independent predictors. Pretreatment lactate dehydrogenase, post-treatment lactate dehydrogenase and lactate dehydrogenase decline were not independent predictors. When all patients were stratified by these independent factors into three groups (0 risk vs. 1 or 2 risks vs. 3 or more risks), there were significant differences in progression-free survival rates between the groups (P < 0.0001). Furthermore, there were also significant differences in overall survival rates between the groups (P < 0.0001). Conclusions: Integration of post-treatment neutrophil-to-lymphocyte ratio value with pretreatment factors may lead to the establishment of effective predictive model for disease progression in patients with metastatic clear cell renal cell carcinoma who received first-line targeted therapies.