The significance of preoperative serum carcinoembryonic antigen levels in the prediction of lymph node metastasis and prognosis in locally advanced gastric cancer: a retrospective... oleh Keshen Wang, Xiangyan Jiang, Yanxian Ren, Zhijian Ma, Xiaocheng Cheng, Fan Li, Jingying Xiao, Zeyuan Yu, Zuoyi Jiao