“…The percentage of high/positive COX-2 expression was >50% in 15 studies,6,8,10,11,13–19,21,22,31,34,36 and the remaining 10 studies shared the percentage of high/positive COX-2 expression <50% 7,9,12,20,21,23,24,32,33. Among these studies, ESCC was investigated in 17 studies,6,9–13,16,18,19,21–24, 31–34,36 EADC was investigated in 5 studies,7,8,14,17 and another 3 studies evaluated both histological types 15,20,21. The patients in 17 studies were treated by surgery only;7–11,13–15,17,19,21,22,24,31,33,34 the surgery plus additional chemotherapy or radiotherapy was applied in 8 studies 6,12,16,18,20,23,32,36…”