Anti-PD-1 plus anti-angiogenesis combined with chemotherapy in patients with HER2-negative advanced or metastatic gastric cancer: a multi-institutional retrospective study - Xu, Tongpeng; Wang, Wenjie; Bao, Ruikang; Xia, Xihua; Zhang, Junling; Huang, Mengli; Chen, Xiaofeng; Wang, Rong; Zhang, Hao; Liu, Xisheng; Li, Qiong; Shu, Yongqian (Journal of Gastrointestinal Oncology, 2023)