“…Thirty inclusions explicitly stated using a clinical staging method [12,14,16,21,31,33,36,, while a combination of clinical and pathological staging was used in 3 studies [61][62][63]. The remaining 32 studies did not specify the staging method [11,13,15,17,18,20,32,34,35,37,. More recent staging systems TNM6 (2002, n = 9), TNM7 (2009, n = 23), and TNM8 (2017, n = 3) were used in 35 publications [11-13,15,16,33, 35,36,38,39,42,46,47,49,51,52,54-57,59,61-63,65,66,68,72,73,75,7 6,78,80,81,85].…”