Objective To evaluate the prognostic value of C-reactive protein (CRP), performance status (PS), lactate dehydrogenase (LDH), albumin (ALB) and derived neutrophil-to-lymphocyte ratio (dNLR) composite index (C-PLAN) as a prognostic indicator in advanced esophageal cancer patients treated with immune checkpoint inhibitor (ICI).

Methods Hematologic indexes of 147 patients with advanced esophageal cancer treated by ICI in the Affiliated Hospital of Yangzhou University were collected before the first immunotherapy. CRP, PS, LDH, ALB and dNLR were scored and added to obtain C-PLAN index. Chi-square test was used to analyze the correlation between C-PLAN index and clinicopathological features; Kaplan-Meier survival curve was used to analyze the effects of C-PLAN index on overall survival (OS) and progression-free survival (PFS). Univariate and multifactor Cox proportional regression models were used to analyze whether C-PLAN index could be used as an independent factor affecting prognosis.

Results A total of 147 patients with advanced esophageal cancer were divided into low-risk group (scored < 2, n=46) and high-risk group (scored ≥2, n=101) according to C-PLAN index. C-PLAN index was not correlated with age, sex, PS score, smoking, clinical stage, body mass index, pathological type, treatment strategy and operation (P>0.05). PFS and OS in the low-risk group were significantly better than those in the high-risk group (P < 0.001). In univariate Cox regression analysis, C-PLAN index was the influencing factor of PFS (P < 0.001) and OS (P=0.002). In multivariate Cox analysis, C-PLAN index was an independent prognostic factor of PFS (P=0.001) and OS (P=0.006).

Conclusion C-PLAN index can be used as a reliable clinical index to predict the prognosis of patients with advanced esophageal cancer treated by ICI.