E, experimental group; C, control group; RCT, randomized controlled trial; /, no data; subgroup 1, control group (non-bevacizumab and chemotherapy drug combination); subgroup 2, control group (bevacizumab and chemotherapy drug combination). Outcome measures: ① disease progression rate; ② disease progression-free survival; ③ 1-year survival rate; ④ incidence of adverse events; ⑤ objective remission rate.