Here, FOLFIRI, Irinotecan+5-Fluorouracil+Leucovorin; IFL, Irinotecan + 5-Fluorouracil; IROX, Irinotecan + Oxaliplatin; FLIRI, Irinotecan + 5-Fluorouracil + Folic acid; XELIRI, Irinotecan + capecitabine + bevacizumab; Lv5FU2-IRI, Irinotecan + 5-Fluorouracil + Folic acid; U, Unknown; Invader UGT1A1 Molecular Assay kit, Third Wave Technologies, Madison, WI, USA; WHO, World Health Organization criteria; NDP, Nedaplatin

Assessment of studies by NOS indicated that the included studies were of high quality where the NOS score ranged from ‘7’ to “9’, as shown in Supplementary Table S1.