First-line or Second-Line PD-1 Inhibition in Advanced Oesophageal Squamous Cell Carcinoma: A Prospective, Multicentre, Registry Study.

What is known and objective First-line and second-line immunotherapy with programmed death-1 (PD-1) inhibitors both improve overall survival in patients with advanced oesophageal squamous cell cancer (ESCC). This study explored survival differences between first-line and second-line PD-1 inhibition in advanced ESCC. Methods This registry study included 167 patients with advanced ESCC who were exposed to PD-1 inhibitors in either a first-line or a second-line setting between 15 January 2019 and 31 October 2020. The primary endpoint was overall survival, and secondary endpoints included overall tumour response, progression-free survival (PFS) and PFS2. A propensity score-matching (PSM) analysis was performed using the nearest-neighbour method. Results and discussion Sixty-one patients started first-line treatment with chemotherapy and a PD-1 inhibitor (Group 1), while 106 started chemotherapy as the first-line choice and received a PD-1 inhibitor as the second-line choice (Group 2). The median PFS was 7.1 months in Group 1 and 4.1 months in Group 2 (log-rank p = 0.001). The median PFS2 was 7.1 months in Group 1 and 7.4 months in Group 2 (log-rank p = 0.4). Before PSM, the median overall survival was 13.5 months in Group 1 and 14.1 months in Group 2 (log-rank p = 0.9), and the sensitivity analysis showed consistent results (14.0 vs. 14.1 months). After PSM, the median overall survival rates for Group 1 (n = 61) and Group 2 (n = 61) were 13.5 and 13.1 months (log-rank p = 0.7) respectively. What is new and conclusion In this study, patients with advanced ESCC who received first-line or second-line PD-1 inhibitors seemed to have comparable overall survival.