“…Among the included studies, twenty-four studies were retrospective, and two studies were prospective. The diagnoses included gastric cancer (n = 1,980) (14,16,17,28,34), esophageal cancer (n = 296) (18, 20, 36), hepatic cancer (n = 535) (23,24), pancreatic cancer (n = 1,160) (15,25,26,(31)(32)(33), colorectal cancer (n = 4,328), (19,21,22,27,29,30,35,37) and colorectal liver metastases (n = 430) (38,39). The pooled average age of 5,784 patients was 65.6 (95% CI: 63.7-67.6) years (14-16, 18-21, 23-27, 30-33, 35-39).…”