Statistical analysis
We tested no formal hypotheses in this study. For descriptive analysis of clinical data, categorical data were summarized as counts with percentages and continuous data were summarized as medians with ranges. PFS was depicted using Kaplan–Meier curves and were compared between groups using the log-rank test. Statistical analyses were conducted using SAS 9.4 (SAS Institute, Inc., Cary, North Carolina, USA).Biomarker analyses were performed in R v2.0.0 and maftools v2.8.0. Fisher’s exact test was used to compare ctDNA mutations between groups. Correlation between All tests were two-sided. Adjusted 