Thiol/disulfide homeostasis: A prognostic biomarker for patients with advanced non-small cell lung cancer?

Figures & data

Table 1 Characteristics of subjects

	Lung cancer group n:35	Control group n:35	P
Age	61.8 ± 7.9	60.8 ± 6.8	0.882
Gender			0.784
Male n (%)	31 (88.6)	30 (85.7)
Female n (%)	4 (11.4)	5 (14.3)
Native thiol (μmol/l)	266.1 ± 64.5	313 ± 78.2	0.008
Disulfide (μmol/l)	17.2 ± 5.6	20.2 ± 4.4	0.021
Total thiol (μmol/l)	300.6 ± 68.9	354 ± 79.5	0.004
Native thiol/disulfide	17.5 ± 9.3	16.1 ± 5.06	0.880

Numerical data are shown as mean ± standard deviation.

Table 2 Patients characteristics

Characteristic	n (%)
Histology
Adenocarcinoma	9 (25.7)
Squamous cell carcinoma	13 (37.1)
Other and uncertain	13 (37.1)
KPS
≥80	22 (32.8)
<80	13 (19.4)
cT
T1	3 (8.6)
T2	10 (28.6)
T3	3 (8.6)
T4	19 (54.3)
cN
N1	5 (14.3)
N2	18 (51.4)
N3	12 (34.3)
Chemotherapy
Yes	19 (54.3)
No	16 (45.7)
Radiotherapy
Yes	3 (8.6)
No	32 (91.4)
No. of metastatic sites
≤2	19 (54.3)
>2	16 (45.7)
Metastatic sites
Brain	7 (20)
Lung	11 (31.4)
Bone	14 (40.0)
Hepatic	7 (20.0)
Adrenal gland	6 (17.1)
Lymph node	31 (88.6)
Malignant pleural effusion	5 (14.3)

KPS, Karnofsky performance status.

T, primary tumor; N, regional lymph node, TNM staging system for lung cancer (seventh edition of the American Joint Committee on Cancer (AJCC)).

Table 3 Means, standard deviations, and correlations among variables

Variables	Mean	SD	1	2	3	4	5	6
OS	5.37	2.45
Disulfide (μmol/l)	18.6	5.3	0.341*
Native thiol (μmol/l)	288.9	74.8	0.345*	0.213*
Total thiol (μmol/l)	326.3	78.4	0.388*	0.366*	0.987^±
Native thiol/disulfide	16.8	7.5	−0.073	−0.693^±	0.545^±	0.434^±
KPS	80 (40–90)^†		0.156	0.096	−0.421*	0.407*	0.185
Age	61.8	7.9	−0.314*	−0.102	−0.084	−0.047	−0.148	−0.358*

*P < 0.05.

^±P < 0.001.

^†Median value (min − max).

SD, standard deviations; OS, overall survival; KPS, Karnofsky performance status.

Table 4 Results of the regression analysis with OS as criterion variable

H	Unstandardized coefficients		Standardized coefficients Beta	t	P
	B	Std error
Gender	2.360	0.987	0.311	2.391	0.024
KPS	4.293	1.411	0.712	3.043	0.005
Lung metastases	−2.10	0.684	−0.404	−3.071	0.005
Native thiol	0.240	0.005	0.620	4.298	<0.001

Figure 1 The ROC curve showing the sensitivity and specificity of the plasma thiol levels due to disease development of NSCLC.

Figure 2 The ROC curve showing the sensitivity and specificity of the plasma disulfide levels due to disease development of NSCLC.

Figure 3 Kaplan–Meier OS curves for patients with NSCLC, stratified by plasma native thiol levels at the time of diagnosis.

Figure 4 Kaplan–Meier OS curves for patient with NSCLC, stratified by plasma disulfide levels at the time of diagnosis.