Interferon Gamma-Induced Protein (IP-10) as Potential Biomarker for Cancer-Related-Fatigue: Results from a 6-month Randomized Controlled Trial

Figures & data

Figure 1. CONSORT flowchart of included patients. Flowchart of patients randomized to either the cognitive behavior therapy condition or the waiting-list condition. Only the participants who completed both baseline and follow-up IP-10 assessment were compared to non-fatigued patients in terms of baseline cytokine concentrations. Abbreviations: CBT: cognitive behavior therapy; WL: waiting list.

Table 1. Baseline characteristics of fatigued and non-fatigued patients (cross-sectional baseline comparison) and of fatigued patients in the therapy and waiting list condition (longitudinal comparison).

	Cross-sectional baseline comparison			Longitudinal comparison
	Fatigued (n = 39)	Non-fatigued (n = 22)	p value	CBT (n = 26)	WL (n = 13)	p value
Male/female	19/20	11/11	0.923	14/12	5/8	0.365
Age (years)	49.4 ± 9.9	48.3 ± 10.5	0.674	48.9 ± 9.2	50.5 ± 11.4	0.620
Time since cancer treatment (months)	51.6 ± 53.4	60.5 ± 43.6	0.212	54.0 ± 60.7	46.9 ± 36.6	0.592
Cancer diagnosis (%)
Breast cancer	14 (36)	9 (41)		9 (35)	5 (38)
Head and neck cancer	8 (21)	2 (9)		6 (23)	2 (15)
Testicular cancer	3 (8)	3 (14)		3 (12)	0
(Non)Hodgkin	5 (13)	3 (14)		2 (8)	3 (23)
Prostate cancer	3 (8)	0		2 (8)	1 (8)
Thyroid cancer	2 (5)	0		2 (8)	0
Other solid cancers	4 (10)	5 (23)		2 (8)	2 (15)
Cancer treatment (%)
Surgery only	4 (10)	2 (9)		3 (12)	1 (8)
Surgery and CT	6 (15)	4 (18)		6 (24)	0
Surgery and RT	5 (13)	2 (9)		3 (12)	2 (15)
Surgery and RI	1 (3)	0		1 (4)	0
Surgery and IT	2 (5)	1 (5)		0	2 (15)
Surgery, RT and CT	5 (13)	4 (18)		4 (15)	1 (8)
Surgery, RT, and HT	1 (3)	0		1 (4)	0
Surgery, RT, and RI	1 (3)	0		1 (4)	0
Surgery, CT, and HT	6 (15)	2 (9)		4 (15)	2 (15)
Surgery, RT, CT, and HT	4 (10)	4 (18)		2 (8)	2 (15)
CT only	1 (3)	1 (5)		0	1 (8)
CT and RT	2 (5)	1 (5)		1 (4)	1 (8)
RT only	1 (3)	1 (5)		0	1 (8)

Data are presented as absolute numbers, as mean ± standard deviation, or as frequencies with percentages in brackets. Independent samples t tests (age), chi square tests (sex), and Mann Whitney-U tests (time since cancer treatment) were performed. Abbreviations: CBT: cognitive behavior therapy; CT: chemotherapy; HT: hormonal therapy; IT: immunotherapy; RI: radioactive iodine; RT, radiotherapy; WL: waiting list.

Figure 2. Longitudinal comparison of IP-10 concentration between CBT and WL condition. X-axis: Measurement at baseline and follow-up in the CBT and WL condition. Y-axis: IP-10 concentration in pg/mL. Abbreviations: CBT: cognitive behavior therapy; WL: waiting list.

Table 2. Cross-sectional and longitudinal comparison of fatigue severity and IP-10 concentration.

	Cross-sectional baseline comparison			Longitudinal comparison
	Fatigued (n = 39)	Non-fatigued (n = 22)		CBT condition (n = 26)			WL condition (n = 13)
			P-value	Baseline	Follow-up	P-value	Baseline		Follow-up	P-value	P-value †
CIS-Fatigue score
Median (P25%-P75%)	44 (41-51)	11 (8-14)	<0.0001*	44 (40-51)	22 (16-30)	<0.0001*	46 (42-50)	40 (37-46)		0.040*
No. of patients with CIS-Fatigue ≥35	39/39	0/22		26/26	3/26	<0.0001*	13/13	11/13		0.1654
Median relative change from baseline to follow-up				−49% (-31% to -64%)			−10% (-3% to -21%)				0.0015*
IP-10 concentration (pg/mL)
Median (P25%-P75%)	738.0 (537.0-1110.0)	902.4 (577.3-1086.0)	0.7411	670.3 (518.5-1093.0)	750.5 (563.0-1367.0)		967.1 (660.1-1235.0)	880.0 (647.8-1189.0)
Median relative change from baseline to follow-up				+13% (+2% to +54%)			−5% (-24% to +46%)			0.1178*

Cross-sectional baseline comparison: the median baseline fatigue score and baseline IP-10 concentration was compared between the fatigued patients (pooled CBT and WL group) versus the matched non-fatigued patients.

Longitudinal comparison: the median relative change in fatigue score and IP-10 concentration from baseline to follow-up was compared between the CBT group and the WL group.

Only non-parametric tests were used.

Abbreviations: CBT: cognitive behavior therapy; P25%: 25^th percentile; P75%: 75^th percentile; WL: waiting list.

Notes: * P < 0.05; † P-value for median relative change from baseline to follow-up