Prognostic value of liver metastasis in patients with esophageal squamous cell carcinoma treated with nivolumab.

Nivolumab has been approved for unresectable recurrent advanced esophageal cancer. The present study aimed to provide real-world data on diverse patient profiles, including the elderly and those with poor performance status, while exploring therapeutic efficacy biomarkers. This retrospective study included 42 patients with esophageal cancer who received nivolumab after second- or later-line treatment at Kyoto Prefectural University of Medicine (Kyoto, Japan) from February 2020 to December 2021. The study evaluated real-world patient data for the outcomes, safety and clinical characteristics impacting efficacy. The median patient age was 70 years (range, 52-80), and 36 patients (85%) were male. A total of 22 patients (52%) were ≥70 years of age, and three (7%) had an Eastern Clinical Oncology Group Performance Status of 2, which was not included in the clinical trial. The response and disease control rates were 26 and 78%, respectively. With a median follow-up period of 7.9 months, the median progression-free survival and overall survival were 3.5 (95% CI, 2.0-6.0) and 19 (95% CI, 6.4-not reached) months, respectively. Patients with liver metastases had significantly worse progression-free survival and overall survival, while lung and lymph node metastases did not clearly impact nivolumab efficacy. Multivariate analysis revealed that liver metastases may predict both worse progression-free survival [hazard ratio (HR) 2.37; 95% CI, 1.07-5.24; P=0.03) and overall survival (HR, 2.75; 95% CI, 1.00-7.53; P=0.04). This study provided real-world evidence of nivolumab's favorable efficacy across diverse profiles, including the elderly and those with impaired performance status. No serious immune-related adverse events occurred and liver metastasis emerged as a predictive biomarker for nivolumab efficacy in esophageal squamous cell cancer.