Diagnostic value of combined detection of plasma cfDNA concentration and integrity in NSCLC

Figures & data

Table 1. The clinical characteristics of patients with NSCLC.

Clinical characteristics	NSCLC patients (n = 71)
	No.	%
Age (years)
≤60	34	47.89
>60	37	52.11
Sex
Male	41	57.75
Female	30	42.25
UICC primary tumor
T1	26	36.62
T2	22	30.99
T3	10	14.08
T4	13	18.31
UICC regional lymph nodes
N0	39	54.93
N1	10	14.08
N2	11	15.49
N3	11	15.49
UICC distant metastasis
M0	51	71.83
M1	20	28.17
UICC stage
I	23	32.39
II	14	19.72
III	14	19.72
IV	20	28.17

UICC: Union for International Cancer Control.

Figure 1. Comparison of plasma cfDNA concentration in NSCLC patients and healthy controls.

(A) The concentration of LINE1-97 bp fragment was significantly higher in NSCLC patients with stage I/II and stage III/IV than that of healthy controls. (B) The concentration of LINE1-97 bp fragment was significantly higher in NSCLC patients with stage I/IV than that of healthy controls. (C & D) Receiver operating characteristic curves for distinguishing NSCLC patients from healthy controls.

AUC: Area under the curve.

Figure 2. Comparison of plasma cfDNA concentration in NSCLC patients and healthy controls.

(A) The concentration of LINE1-266 bp fragment was significantly higher in NSCLC patients with stage I/II than that of healthy controls. (B) The concentration of LINE1-266 bp fragment was significantly higher in NSCLC patients with stage I/IV than in healthy controls. (C & D) Receiver operating characteristic curves for distinguishing NSCLC patients from healthy controls.

AUC: Area under the curve.

Table 2. Comparison of plasma cfDNA concentration, integrity between NSCLC patients and healthy controls.

	Controls	Stage I/II	Stage III/IV	Stage I/IV
No. pts	53	37	34	71
LINE1-97 (ng/ml):
– Mean	12.40	20.94	23.10	21.97
– Median	12.14	19.47	21.20	20.00
– p-value		<0.0001	<0.0001	<0.0001
LINE1-266 (ng/ml):
– Mean	3.19	4.36	4.00	4.19
– Median	2.96	3.90	3.79	3.80
– p-value		0.0296	0.0510	0.009
LINE1-266/97 (ng/ml):
– Mean	0.29	0.24	0.22	0.23
– Median	0.26	0.19	0.20	0.19
– p-value		0.0411	0.0310	0.0025

Table 3. Diagnostic value of plasma cfDNA concentration and integrity in non-small-cell lung cancer patients.

	Cut-off (ng/ml)	Sensitivity	Specificity	AUC (95% CI)
LINE1-97:
Stage I/II	18.73	0.59	0.87	0.772 (0.673–0.871)
Stage III/IV	16.30	0.74	0.79	0.796 (0.692–0.900)
Stage I/IV	17.56	0.62	0.85	0.783 (0.705–0.862)
LINE1-266:
Stage I/II	3.23	0.70	0.60	0.632 (0.508–0.756)
Stage III/IV	3.73	0.56	0.70	0.642 (0.523–0.762)
Stage I/IV	3.73	0.58	0.70	0.637 (0.540–0.734)
LINE1-266/97:
Stage I/II	0.20	0.54	0.77	0.655 (0.533–0.776)
Stage III/IV	0.20	0.50	0.77	0.661 (0.541–0.782)
Stage I/IV	0.20	0.52	0.77	0.658 (0.563–0.753)

AUC: Area under the curve.

Figure 3. Comparison of plasma cfDNA integrity in NSCLC patients and healthy controls.

(A) The plasma cfDNA integrity LINE1-266/97 was significantly lower in NSCLC patients with stage I/II and stage III/IV than in healthy controls. (B) The integrity of LINE1-266/97 was significantly lower in NSCLC patients with stage I/IV than in healthy controls. (C & D) Receiver operating characteristic curves for distinguishing NSCLC patients from healthy controls.

AUC: Area under the curve.

Figure 4. Correlation between plasma cfDNA and lymph node metastasis in NSCLC patients.

(A–C) There was no significant difference in plasma cfDNA concentration and integrity between lymph node metastasis (LNM)-positive and LNM-negative patients. (D–F) Receiver operating characteristic curves for distinguishing LNM-positive patients from LNM-negative patients.

AUC: Area under the curve.

Figure 5. Diagnostic values of combined plasma cfDNA concentration and integrity in NSCLC patients.

(A) ROC curves of LINE1-97, LINE1-266 and LINE1-266/97 for distinguishing NSCLC patients with stage I/II from healthy controls. (B) ROC curves of the combination of plasma cfDNA concentration (LINE1-97, LINE1-266) and integrity (LINE1-266/97) for distinguishing NSCLC patients with stage I/II from healthy controls.

AUC: Area under the curve.

Table 4. Diagnostic value of combined plasma cfDNA concentration and integrity for NSCLC patients.

Marker	AUC	Sensitivity	Specificity	p-value
LINE1-97	0.772	0.59	0.87	<0.0001
LINE1-266	0.632	0.70	0.60	0.0296
LINE1-266/97	0.655	0.54	0.77	0.0411
LINE1-97 + LINE1-266	0.781	0.62	0.85	<0.0001
LINE1-97 + LINE1-266/97	0.781	0.62	0.85	<0.0001
LINE1-266 + LINE1-266/97	0.733	0.73	0.62	<0.0001
LINE1-97 + LINE1-266 + LINE1-266/97	0.781	0.62	0.85	<0.0001