2.3. Data extraction and quality assessment

We developed a standardized data collection form for data extraction, which consisted of the following data: first author, publication year, origin of study, disease stage, patient age, study sample size, therapeutic strategies, follow-up time, and study design. Two authors independently applied the standardized data form to collect the data for analysis and compared those outcome data independently. Another author would handle the discrepancy if there existed one. The main outcomes for analysis in our meta-analysis included 1-year OS and PFS rates, and hazard ratios (HRs) of OS and PFS. We would apply the Jadad scale^[16] to evaluate the quality of RCTs and the Newcastle-Ottawa Scale (NOS),^[17] which included 3 factors: patient selection, comparability of the study groups, and assessment of outcome, to assess the quality and risk-of-bias of observational studies. For observational study, we would assign a score of 0 to 9 (allocated as stars) to each study using the NOS and here we defined the high-quality study as one with a quality score ≥7. In our current meta-analysis, we used the name of the first author and year of publication for identification.