Characteristics and Demographics of Included Studies.

R = retrospective; P = prospective nonrandomized; WO = washout group; NWO = no washout group; N: number of patients; n : number of events; NS = not stated; LR = local recurrence; AR = anastomotic recurrence; DFU = duration of follow-up.R = 回顾性（retrospective）；P = 前瞻性非随机（prospective nonrandomized）；WO = 洗脱组（washout group）；NWO = 非洗脱组（no washout group）；N：患者例数（number of patients）；n：事件数（number of events）；NS = 未提及（not stated）；LR = 局部复发（local recurrence）；AR = 吻合口复发（anastomotic recurrence）；DFU = 随访时长（duration of follow-up）。