“…Figure 1 depicts the flow of retrieving the articles. Twenty-three studies included samples comprised of patient with gastrointestinal (GI) cancers, 22,24,26,[28][29][30][31][32][33]35,36,39,40,42,49,50,53,55,57,58,60,65,67 seven with urological cancers, 25,27,[45][46][47]62,68 nine on various cancers, 34,38,43,48,51,52,56,59,64 three with head and neck cancers, 21,23,41 and one with gynecological, lung, oral, and brain (tumor) cancers, respectively. Of the 48 studies, 39 [21][22][23][24][25][26][27]…”