Table 1.

Selected proposed biomarkers.

	Selected biomarkers of interest	Studied in	Ref.
Antigens	CA19-9, CEA	Plasma	Locker et al. [26]
Proteins	IGFBP 2, IGFBP 3	Plasma	Yoneyama et al. [27]
	SYCN, REG1B, AGR2	Plasma	Makawita et al. [65]
	ICAM1, OPG	Plasma	Brand et al.
	MMP-9, DJ-1, A1BG,	Pancreatic fluid	Tian et al. [66]
	thrombospondin-2	Plasma	Kim et al.
Metabolites	Glucitol, palmitate, xylitol	Plasma	Mayerle et al. [30]
ncRNAs	miR-1290	Plasma	Cao et al. [32]
	miR-486-5p	Plasma	Li et al. [33]
CTCs		Plasma	Bidard et al. [35], de Albuquerque et al. [36], Kulemann et al. [37]
cfDNA		Plasma	Tjensvoll et al. [67]
Exosomes	GPC1+crExos	Plasma	Melo et al. [68]

ncRNAs: noncoding RNAs; CTC: circulating tumor cells; cfDNA: circulating free DNA.