Maximum Efficacy of Immune Checkpoint Inhibitors Occurs in Esophageal Cancer Patients With a Low Neutrophil-to-Lymphocyte Ratio and Good Performance Status Prior to Treatment.

Background/aim: Immune checkpoint inhibitors (ICIs) play an important role in the treatment of esophageal cancer (EC). However, few patients achieve long-term survival, and some patients develop serious immune-related adverse events (irAEs). Reliable predictive biomarkers of efficacy and safety need to be established in order to improve efficacy. We retrospectively analyzed the outcomes of nivolumab monotherapy on EC at Showa University, Department of Medicine, to identify biomarkers and characteristics of patients who benefit from ICI monotherapy.

Patients And Methods: Eighty-six patients with EC who received nivolumab monotherapy were included in the present study. Patient characteristics, efficacy, and safety were analyzed. A multivariable analysis evaluated the correlation among overall survival (OS), progression-free survival (PFS), best overall response (BOR), irAEs, and the following variables: sex, age, performance status (PS), neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP) level, albumin level, and body-mass index before treatment.

Results: Median PFS was 3.1 months, and median OS was 9.0 months. In multivariable analysis, pretreatment PS, NLR, and sex were significantly correlated with OS and PFS. NLR <3.3 predicted longer survival (median OS 17.5 vs. 6.4 months for NLR ≥3.3; p<0.001). Median OS was 10.6 months for PS 0-1 and 1.3 months for PS 2-3 (p<0.001). NLR remained significantly predictive in the PS 0-1 group. The development of irAEs was significantly associated with increased OS and PFS.

Conclusion: Patients with low NLR and good PS before treatment may maximize the benefits of ICIs. A low NLR may be an indicator of higher immunocompetence for anti-tumor immunity, suggesting that NLR may be a convenient predictive biomarker in daily practice.