Table 3.

Clinical Studies of Glutathione Levels in Gastrointestinal Tumors

Study	#Ptsa	Tumor Glutathione Levelb	γGTc	Controld	Ratioe (T/C)
Colorectal
(Barranco et al. 2000)	41 Colon	15.33 ± 1.4 nmol/mg-protein	Y	P	1.9*
	24 Rectum	16.56 ± 23			1.3*
(Baur & Wendel 1980)	8 Colon	12.6 nmol/mg-protein	Y	P	1.3
(Berger et al. 1994)	5 Colon	11.1 ± 1.7 nmol/mg-protein	Y	P	1.5
(Butler et al. 1994)	25 Polyp	~26.8 nmol/mg-protein	Y	P	1.4*
	58 Colon	~25.1			1.3*
(Grubben et al. 2006)	37 Colon		Y	H	0.75f
(Hengstler et al. 1998)	23 Colon	5.6 μg/mg-protein	Y	P	0.77
(Mekhail-Ishak et al. 1989)	17 Colon	5.7 ± 1.1 μmol/g-tissue	Y	P	1.9*
(Murawaki et al. 2008)	41 Colorectal	~1.3 μmol/g-tissue	Y	P	~0.4*
(Oliva et al. 1997)	43 Colorectal	11.1 ± 4 nmol/mg-protein	Y	P	3.1*
(Ozdemirler et al. 1998)	10 Colorectal	39.9 ± 11.0 nmol/mg-protein	Y	P	1.4*
(Redmond et al. 1991)	23 Colon	57.47 ± 5.06 nmol/mg-protein	Y	P	1.3*
(Siegers et al. 1984)	10 Colon	39 ± 13 nmol/mg-protein	Y	P	0.87
	8 Sigmoid	34 ± 4			0.45*
	113 Rectum	52 ± 12			0.65
(Skrzydlewska et al. 2001)	55 Colorectal	~1.1 μmol/g-tissue	Y	P	0.79*
(Skrzydlewska et al. 2005)	81 Colorectal		Y	P
	Stage II	174 ± 36 nmol/g-tissue			1.04*
	Stage III	156 ± 39			0.93*
	Stage IV	150 ± 48			0.89*
(Skrzydlewska et al. 2003)	62 Colorectal	175 ± 42 nmol/g-tissue	Y	P	1.1
Gastric
(Czeczot et al. 2005)	10	1.81 ± 0.83 μmol/mg-protein	Y	P	0.69
(Eapen et al. 1998)	49	68.2 ± 24.2 nmol/mg-protein	Y	P	0.94
				H	1.5*
(Engin & Ferahkose 1990)	9	0.791 ± 0.072 mg/g-tissue	Y	P	1.1
				H	0.46*
(Hoppenkamps et al. 1984)	12	31.60 ± 8.83 nmol/mg-protein	Y	P	0.54*
				H	0.67*
(Mun et al. 2004)	13				<1
(Schipper et al. 2000)	15		?
(Skrzydlewska, 2003)	18	392 ± 87 nmol/g-tissue	Y	P	1.2
Esophageal
(Evans et al. 2002)	20 AC,12 SQ	2.2 mM	Y	P	1.0
(Kaur et al. 2008a; Kaur et al. 2008b)	40	38.4 ± 11.9 μg/mg-protein	Y	P	1.2
(Levy et al. 1999)	31			H	<1
(Peters et al. 1993)	6 SQ, 3 AC	36 ± 12 nmol/mg-protein	Y	P	0.95
(Sihvo et al. 2003; Sihvo et al. 2002)	21 AC	1.30 ± 1.30 nmol/mg-protein	?	H	0.45*
(Skrzydlewska, 2003)	18 SQ	315 ± 75 nmol/g-tissue	Y	P	1.4*
Liver
(Abel et al. 2009)	13	0.60 ± 0.05 μmol/g-tissue	Y	P	0.41*
(Abou Ghalia, 2000)	5	0.8 ± 0.04 mM/g-protein	Y	B	0.57
(Corrocher et al. 1986)	7	6.57 ± 6.27 μmol/g-protein	Y	P	0.31*
				H	0.091*
(Czeczot et al. 2006)	15	4.62 ± 2.94 μmol/mg-protein	Y	P	0.84*
(Jungst et al. 2004)	23	0.99 μmol/g-tissue	Y	P	0.64
(Lee et al. 2007)	24	439.8 ± 198.4 μM/g-protein	Y	P	0.61*

^aNumber of patients in the study with AC, adenocarcinoma; SQ, squamous cell carcinoma; or as designated.

^bConcentration of glutathione or thiols in tissue. Numbers in italics indicates reports of non-protein sulfhydryls rather than glutathione.

^cDenotes whether degradation by γ-glutamyltranspeptidase was prevented (Y) or not (N) by sample processing methods.

^dDisease free tissue from healthy controls (H); peritumoral tissue (P) or benign lesion (B).

^eRatio of tumor glutathione to control tissue levels. Gray shading indicates statistically significant T/C<1

^fRatio of peritumoral to control healthy tissue

^*Asterisk indicates statistically significant differences in glutathione levels.