Fig. 5

Assessment of risk of bias. a Risk of bias assessment for each included RCT. The bar chart indicates the distribution of risk-of-bias judgments across the domains. b The funnel plot of each effect size in terms of overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). SQ, sequence generation; AL, allocation concealment; BL, blinding; IN, incomplete outcome data; SL, selective outcome reporting; OT, other potential threats to validity; SE, standard error; HR, hazard ratio; OR, odds ratio