Clinical utility of the C‐reactive protein:albumin ratio in non‐small cell lung cancer patients treated with nivolumab

Abstract Background Nivolumab is a second‐line chemotherapy for non‐small cell lung cancer (NSCLC). This study explored the impact of clinical biomarkers such as neutrophil:lymphocyte ratio (NLR), C‐reactive protein:albumin ratio (CAR), and modified Glasgow prognostic score on the efficacy and outcome of nivolumab monotherapy in previously treated NSCLC patients. Methods We retrospectively analyzed advanced or postoperative recurrence of NSCLC in 113 patients in two Japanese facilities from January 2015 to December 2019. Optimal cutoff values of NLR and CAR were assessed by the area under the receiver operating characteristic curves predicting death events to conduct regression analysis. Baseline values and values collected eight weeks after nivolumab treatment were measured to investigate time‐series changes of these markers. Results The patients showed median overall survival (OS) and progression‐free survival (PFS) of 14.0 months and 2.3 months, respectively, with both being significantly longer in patients with partial response (PR) than in patients with progressive disease (PD). Optimal cutoff levels for NLR and CAR were 5.8 and 0.83, with significant decrease in CAR ( P = 0.002) from baseline levels in PR patients and significant increase in PD patients. Baseline CAR ≥0.83 was significantly associated with one‐year mortality events and overall survival (OS), and multivariate analysis showed significant association of age ≤70 years, an Eastern Cooperative Oncology Group performance status score of 2 or 3, and a baseline CAR ≥0.83 with inferior OS. Conclusions For second‐line nivolumab therapy, evaluation of baseline CAR and subsequent changes in CAR may be predictive of therapeutic response to nivolumab and long‐term survival in NSCLC patients. Key points Significant findings of the study The baseline value of C‐reactive protein:albumin ratio was significantly associated with one‐year mortality and overall survival in non‐small cell lung cancer patients treated with nivolumab. What this study adds Time‐series change of C‐reactive protein:albumin ratio may be useful for predicting the treatment efficacy in patients treated with nivolumab.