Current Challenges in Volatile Organic Compounds Analysis as Potential Biomarkers of Cancer

Table 2

Volatile organic compounds detected in both the exhaled breath of lung cancer patients and the HS of lung cancer tissues in studies that simultaneously investigated VOCs ex vivo and in vivo. Only VOCs that have also been previously detected in the HS of cancer cells in vitro in other studies are listed.

Class	Volatile organic compound	Reference	In vitro study reference
Alkanes	Pentane	[28]	[72]
	Hexane	[28, 91]	[72]
	Octane	[91]	[80]
Branched alkanes	2-Methylpentane	[28, 91]	[72]
	3-Methylpentane	[28]	[72]
	2,3,4-Trimethylpentane	[91]	[72]
	4-Methyloctane	[91]	[15, 72]
Alkenes	2-Methyl-1-pentene	[91]	[80]
	2,4-Dimethyl-1-heptene	[91]	[72, 79, 80]
Alcohols	Ethanol	[28, 91]	[79, 80, 82]
	1-Propanol	[28]	[72]
Aldehydes	Acetaldehyde	[28, 91]	[15, 72, 74, 75, 81, 82, 125]
	Acrolein	[91]	[15]
	Hexanal	[91]	[15, 72, 74, 80, 122, 125]
	3-Methylbutanal	[91]	[72, 122]
	2-Methylpropanal	[91]	[15, 72, 80, 122]
	2-Methylbutanal	[91]	[72, 122]
	Benzaldehyde	[28, 91]	[15, 69, 70, 79, 122]
Ketones	Acetone	[28, 91]	[70, 80]
	2-Butanone	[28, 91]	[15, 72, 79]
	2-Pentanone	[28, 91]	[79, 80, 122]
	2-Hexanone	[91]	[79]
	6-Methyl-5-hepten-2-one	[91]	[70]
Carboxylic acids	Acetic acid	[91]	[82, 123]
Ethers	Diethyl ether	[28]	[79]
Pyrroles	Pyrrole	[91]	[79, 80]
Nitriles	Acetonitrile	[28, 91]	[15, 79, 122]
Aromatics	o-Xylene	[92]	[79, 123]
	p-Xylene	[28, 92]	[123]
	Ethylbenzene	[28, 92]	[123]
	Styrene	[92]	[79, 123]