Plasma Endoglin is Associated with Favorable Outcome for Pemetrexed-Based Therapy in Advanced Non-Small Cell Lung Cancer

Figures & data

Figure 1 Enrollment diagram of the retrospective study. Flow chart shows the number of patients who were eligible, enrolled into the study and included in the final analysis. ECOG, Eastern Cooperative Oncology Group.

Figure 2 Different oncology-related protein expression levels between pemetrexed-based therapy responders and nonresponders. Plasma samples at baseline collected from (A) 3 responders (Nos. 15, 17 and 20) and (B) 3 nonresponders (Nos. 24, 27 and 34) analyzed through a human oncology array. Black frames present evident expression differences of specific proteins. (C) Spot intensity quantified using positive control spots (the “0” place) as references. The intensity of 12 proteins in responders and nonresponders with obvious differences were analyzed through unpaired t test. *p < 0.05.

Figure 3 Effects of soluble endoglin, cathepsin S, matrix metalloproteinase 3 and 9 (MMP3 and MMP9) levels on pemetrexed-based chemotherapy responsiveness in the cohort. (A–D) Soluble endoglin, cathepsin S, MMP3 and MMP9 concentration (ng/mL) in responders and nonresponders before the treatment were measured using enzyme-linked immunosorbent assay. The levels of these 4 proteins in responders and nonresponders were compared through unpaired t test. **p < 0.01. (E) Response distribution of high and low endoglin groups on day 120. (F) Waterfall plot of included patients with at least one clinical image record. a, death. b, pemetrexed intolerance. c, distant progression disease. d, effusion accumulation.

Abbreviations: PD, progression disease; SD, stable disease; PR, partial regression.

Figure 4 Level change of soluble endoglin before and after pemetrexed-based therapy in pemetrexed responders. Soluble endoglin concentration in plasma samples of pemetrexed responders at baseline and the time of best response were measured using enzyme-linked immunosorbent assay and analyzed through paired t test. *p < 0.05.

Figure 5 Effects of soluble endoglin, cathepsin S, matrix metalloproteinase 3 and 9 (MMP3 and MMP9) levels on progression-free survival and overall survival. (A–D) Progression-free survival of high- and low groups of endoglin, cathepsin S, MMP3 and MMP9 were analyzed using the Kaplan–Meier method and the log rank test. **p < 0.01. (E) Overall survival of the high- and low-endoglin groups were analyzed using the Kaplan–Meier method and the log rank test. *p < 0.05.

Table 1 Correlation of Pemetrexed-Based Therapy Responsiveness and Clinical, Pathological Factors, and Endoglin Level

Factors	Endoglin (ng/mL)			p value	Pem-Based Response^a			p value
	<25		≥25		Responder		Nonresponder
Gender				0.390				0.523
Female	20		18		19		19
Male	14		19		14		19
Age^b				0.045*				0.850
<65	18		28		21		25
≥65	16		9		12		13
Lymph node				0.452				0.073
N0 – N1	5		8		3		10
N2 – N3	29		29		30		28
ECOG PS				0.041*				0.237
0–1	23		33		24		32
2	11		4		9		6
Smoking				0.028*				0.303
Never	26		19		23		22
Active or quitted	8		18		10		16
Chemotherapy line				0.111				0.242
1	23		31		23		31
>1	11		6		10		7
Pemetrexed				0.209				0.366
Alone	8		4		7		5
Combined^c	26		33		26		33
EGFR status				0.186				0.593
Wild type^d	13		20		14		19
Mutation	15		15		14		16
Unknown	6		2		5		3
Endoglin level								0.003*
<25 ng/mL					22		12
≥25 ng/mL					11		26

Notes: Demographic data were analyzed using the chi-squared test. ^aPem-based response means patients who had progression-free survival of pemetrexed-based therapy longer than 120 days. ^bAge presents the patient’s age at baseline. ^cPemetrexed is combined with platinum. ^d3 patients were ALK translocation and 1 was ROS1 translocation. The association of every factor with endoglin and pem-based response are analyzed through chi-square test or Fisher’s exact test. *p < 0.05.

Abbreviations: ECOG PS, Eastern Cooperative Oncology Group Performance status; EGFR, epidermal growth factor receptor.

Table 2 Univariate and Multivariate Analysis of All Patients with Non-Small Cell Lung Cancer and Treated with Pemetrexed-Based Treatment

Factors	-/Reference	Univariate			Multivariate
		Hazard Ratio	95% CI	p value	Hazard Ratio	95% CI	p value
Gender	Male/female	1.228	0.742–2.032	0.424
Age#	≥65/<65	1.017	0.998–1.036	0.084
Lymph node	N2 – N3/N0 – N1	2.153	1.088–4.260	0.028*	1.950	0.983–3.866	0.056
Performance status	2/0 – 1	1.573	0.879–2.815	0.127
Smoking	Active or quitted/Never	0.714	0.421–1.214	0.214
Chemotherapy line	2/1	1.512	0.864–2.646	0.147
Pemetrexed	Combined/alone	0.669	0.353–1.269	0.219
EGFR status	Mutation/wild type	1.400	0.829–2.366	0.209
Endoglin level	<25/≥25ng/mL	1.994	1.213–3.278	0.007*	1.854	1.125–3.054	0.015*

Notes: ^#Age presents the patient’s age at baseline. All categorical factors are analyzed by univariate and multivariate Cox regression analysis. *p < 0.05.

Abbreviation: EGFR, epidermal growth factor receptor.