Inflammatory prognostic factors in advanced or recurrent esophageal squamous cell carcinoma treated with nivolumab

Background In Japan, nivolumab administration is the standard treatment for patients with unresectable advanced or recurrent esophageal squamous cell carcinoma (ESCC) who are refractory or intolerant to fluoropyrimidines and platinum-based chemotherapy. We determined if inflammatory prognostic factors are useful in patients with ESCC treated with nivolumab monotherapy. Methods The clinical data of patients with ESCC treated with nivolumab monotherapy as the second- or later-line treatment were retrospectively analyzed. Neutrophil/lymphocyte, platelet/lymphocyte, and C-reactive protein/albumin ratios (CAR); prognostic index; and prognostic nutritional index were investigated. Cut-off values for each factor were determined according to overall survival using time-dependent receiver operating characteristic curves. Results During January 2017-June 2021, 93 consecutive patients with ESCC were enrolled from five institutions (median age, 70 years; male, 77%). With a median follow-up period of 9.1 (range, 1.0-34.7) months, the median overall and progression-free survival were 12.8 (95% confidence interval [CI], 9.0-16.6) and 4.0 (95% CI, 2.6-5.4) months, respectively. Of five inflammatory prognostic factors, the cut-off value for CAR was 0.62; prognosis was significantly longer in those with CAR < 0.62 (hazard ratio, 0.39; 95% CI, 0.22-0.67; p = 0.001). Conclusions Inflammatory prognostic factors were useful in predicting prognosis for ESCC patients pretreated with nivolumab, especially for those with CAR < 0.62, suggesting that CAR adequately reflects prognosis.