EGFR mutations are significantly associated with visceral pleural invasion development in non-small-cell lung cancer patients

Figures & data

Table 1 Clinicopathologic characteristics and prognosis of patients

Patient characteristics	Total	Number	%
Total patients	508
Age, years (median, range)	508	61 (25–91)
<60		215	42.3
≥60		293	57.7
Gender	508
Male		264	52
Female		244	48
Smoking status	508
Ever		198	39
Never		310	61
Tumor size, mm (mean ± SD)	508	27.3±14.97
≤30		356	70.1
30–50		116	22.8
>50		36	7.1
Nodule type	508
Non-solid		114	22.4
Solid		394	77.6
pTNM stage (eighth edition)	508
I		343	67.5
II		54	10.6
III		111	21.9
Lymphatic metastasis	508
N0		393	77.4
N1		24	4.7
N2		91	17.9
Histological type	508
ADC		411	80.9
SCC		82	16.1
Othersa		15	3
VPI	508
Yes		229	45.1
No		279	54.9
Tumor–pleural relationship	508
No contacting		147	28.9
Pleural tag type I		69	13.6
Pleural tag type II		99	19.5
Pleural tag type III		30	5.9
Abutting pleural		163	32.1
EGFR mutation status	508
Wild-type		265	52.2
19-del		99	19.5
L858R		122	24
Othersb		22	19.1
Preoperative CEA (ng/mL)	499c
<5		378	75.8
≥5		121	24.2
Postoperative therapy	508
No		227	44.7
Yes		281	55.3
Follow-up time, months (median, range)		50 (3–57)
DFS, months (median, range)		49 (2–57)

Notes:

a Other histological types include large cell lung cancer and adenosquamous carcinoma.

b Other mutation types include 20-ins, G719X, T790M, and L861Q.

c A total of 499 patients underwent preoperative CEA examination in this study.

Abbreviations: ADC, adenocarcinoma; CEA, carcinoembryonic antigen; DFS, disease-free survival; pTNM, pathological TNM; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.

Table 2 Association analysis between clinicopathologic characteristics and VPI

Characteristics	Total	VPI(–)	VPI(+)	P-value for χ^2	Univariate analysis		Multivariate analysis
		n (%)	n (%)		OR (95%CI)	P-value	OR (95%CI)	P-value
	508	279 (54.9)	229 (45.1)
Gender				<0.001
Male	264	165 (59.1)	99 (42.1)		1.00 (reference)		1.00 (reference)
Female	244	114 (40.9)	130 (56.8)		1.90 (1.33–2.71)	<0.001	1.66 (0.88–3.12)	0.119
Smoking status				<0.001
Ever	198	131 (47.0)	67 (29.3)		1.00 (reference)		1.00 (reference)
Never	310	148 (53.0)	162 (70.7)		2.14 (1.48–3.10)	<0.001	1.29 (0.68–2.44)	0.430
Tumor size, mm (mean ± SD)		25.92±14.73	28.98±15.13	0.022a	1.01 (1.00–1.03)	0.023	1.02 (1.01–1.04)	0.041
Nodule type				0.015
Non-solid	114	74 (26.5)	40 (17.5)		1.00 (reference)		1.00 (reference)
Solid	394	205 (73.5)	189 (82.5)		1.71 (1.11–2.63)	0.016	1.48 (0.81–2.72)	0.205
Histological type				<0.001
ADC	411	200 (71.7)	211 (92.1)		1.00 (reference)		1.00 (reference)
SCC	82	69 (24.7)	13 (5.7)		0.18 (0.10–0.33)	<0.001	0.17 (0.06–0.43)	<0.001
Preoperative CEA (ng/mL)	499b			0.042
<5	378	218 (79.3)	160 (71.4)		1.00 (reference)		1.00 (reference)
≥5	121	57 (20.7)	64 (28.6)		1.53 (1.01–2.31)	0.043	0.88 (0.51–1.54)	0.660
EGFR mutation status				<0.001
Wild-type	265	174 (62.4)	91 (39.7)		1.00 (reference)		1.00 (reference)
19-del	99	41 (14.7)	58 (25.3)		2.71 (1.69–4.34)	<0.001	2.13 (1.13–3.99)	0.019
L858R	122	54 (19.4)	68 (29.7)		2.41 (1.55–3.73)	<0.001	2.89 (1.58–5.29)	0.001
Tumor–pleural relationship				<0.001
No contacting	147	147 (52.7)	0 (0.0)		/	/	/	/
Pleural tag type I	69	43 (15.4)	26 (11.4)		1.00 (reference)		1.00 (reference)
Pleural tag type II	99	33 (15.4)	66 (28.8)		3.31 (1.74–6.28)	<0.001	4.19 (2.03–8.65)	<0.001
Pleural tag type III	30	12 (4.3)	18 (7.9)		2.48 (1.03–5.97)	0.043	2.54 (0.98–6.55)	0.054
Abutting pleural	163	44 (15.8)	119 (52.0)		4.47 (2.46–8.13)	<0.001	6.52 (3.26–13.05)	<0.001
Trend					2.35 (2.03–2.72)	<0.001	2.54 (2.14–3.02)	<0.001
Lymphatic metastasis				0.005
N0	393	231 (82.8)	162 (70.7)		1.00 (reference)		1.00 (reference)
N1	24	8 (3.2)	15 (6.6)		2.38 (1.02–5.56)	0.046	1.25 (0.38–4.10)	0.719
N2	91	39 (14.0)	52 (22.7)		1.90 (1.20–3.02)	0.006	0.55 (0.16–1.94)	0.354

Notes:

a P-value for independent t-test.

b A total of 499 patients underwent preoperative CEA examination in this study.

Abbreviations: ADC, adenocarcinoma; CEA, carcinoembryonic antigen; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.

Table 3 Multivariate logistic regression analysis between EGFR mutations and clinicopathologic characteristics

Characteristics	EGFR mutations		EGFR 19-del		EGFR L858R
	OR (95%CI)	P-value	OR (95%CI)	P-value	OR (95%CI)	P-value
Nodule type
Non-solid	1.00 (reference)		1.00 (reference)		1.00 (reference)
Solid	0.39 (0.24–0.65)	<0.001	0.56 (0.29–1.07)	0.080	0.33 (0.18–0.59)	<0.001
Histological type
ADC	1.00 (reference)		1.00 (reference)		1.00 (reference)
SCC	0.08 (0.03–0.24)	<0.001	0.05 (0.01–0.41)	0.005	0.05 (0.01–0.34)	0.003
VPI
No	1.00 (reference)		1.00 (reference)		1.00 (reference)
Yes	2.21 (1.36–3.59)	0.001	1.83 (0.99–3.37)	0.053	2.63 (1.42–4.88)	0.002
Lymphatic metastasis
N0	/		1.00 (reference)		/
N1	/	/	5.02 (1.59–15.81)	0.006	/	/
N2	/	/	1.34 (0.66–2.84)	0.393	/	/
Trend	/	/	1.24 (0.87–1.77)	0.225	/	/

Abbreviations: ADC, adenocarcinoma; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.

Figure 1 DFS curve analysis for postoperative patients based on VPI and EGFR mutations.

Notes: (A) DFS curves in VPI and non-VPI groups. (B) DFS curves in EGFR wild-type and EGFR mutation groups. (C) DFS curves in non-VPI patients stratified by EGFR mutations. (D) DFS curves in VPI patients stratified by EGFR mutations. (E) DFS curves in EGFR wild-type patients stratified by VPI. (F) DFS curves in EGFR mutation patients stratified by VPI.

Abbreviations: DFS, disease-free survival; VPI, visceral pleural invasion.

Table 4 DFS analysis in non-VPI and VPI groups

Variables	Non-VPI				VPI
	Univariate analysis		Multivariate analysis		Univariate analysis		Multivariate analysis
	HR (95%CI)	P-value	HR (95%CI)	P-value	HR (95%CI)	P-value	HR (95%CI)	P-value
Gender
Male	1.00 (reference)		1.00 (reference)		1.00 (reference)		1.00 (reference)
Female	0.47 (0.29–0.77)	0.003	0.80 (0.45–1.41)	0.440	0.56 (0.36–0.86)	0.007	0.71 (0.45–1.13)	0.150
Tumor size (mm)
≤30	1.00 (reference)		1.00 (reference)		1.00 (reference)		1.00 (reference)
30–50	2.61 (1.63–4.16)	<0.001	1.40 (0.81–2.44)	0.230	1.95 (1.21–3.13)	0.006	0.92 (0.54–1.56)	0.742
>50	2.67 (1.26–5.66)	0.011	1.32 (0.57–3.05)	0.513	3.77 (1.99–7.14)	<0.001	1.92 (0.94–3.94)	0.075
Trend	1.87 (1.39–2.53)	<0.001	1.21 (0.83–1.76)	0.316	1.94 (1.45–2.61)	<0.001	1.25 (0.87–1.80)	0.237
Nodule type
Non-solid	1.00 (reference)		1.00 (reference)		1.00 (reference)		1.00 (reference)
Solid	3.97 (1.91–8.24)	<0.001	2.05 (0.91–4.60)	0.083	5.33 (1.95–14.55)	0.001	2.31 (0.80–6.66)	0.121
Histological type
ADC	1.00 (reference)		1.00 (reference)		1.00 (reference)
SCC	2.17 (1.38–3.41)	0.001	1.58 (0.87–2.86)	0.131	1.28 (0.56–2.93)	0.564
Preoperative CEA (ng/mL)
<5	1.00 (reference)		1.00 (reference)		1.00 (reference)		1.00 (reference)
≥5	2.55 (1.62–4.02)	<0.001	2.32 (1.40–3.85)	0.001	2.10 (1.36–3.23)	0.001	1.10 (0.69–1.77)	0.688
Lymphatic metastasis
N0	1.00 (reference)		1.00 (reference)		1.00 (reference)		1.00 (reference)
N1	0.96 (0.23–3.95)	0.956	0.57 (0.14–2.38)	0.437	5.24 (2.58–10.67)	<0.001	3.37 (1.56–7.28)	0.002
N2	5.27 (3.32–8.36)	<0.001	3.24 (1.93–5.43)	<0.001	6.73 (4.60–11.69)	<0.001	5.48 (3.08–9.74)	<0.001
Trend	2.27 (1.80–2.87)	<0.001	1.78 (1.36–2.32)	<0.001	2.69 (2.14–3.37)	<0.001	2.36 (1.78–3.14)	<0.001
EGFR mutation status
Wild-type	1.00 (reference)		1.00 (reference)		1.00 (reference)		/
19-del	0.29 (0.12–0.71)	0.007	0.31 (0.12–0.80)	0.015	1.17 (0.69–1.97)	0.565	/	/
L858R	0.49 (0.26–0.92)	0.028	0.96 (0.47–1.94)	0.899	0.88 (0.51–1.50)	0.631	/	/
Postoperative therapy
No	1.00 (reference)				1.00 (reference)
Yes	2.91 (1.85–4.58)	<0.001	1.40 (0.81–2.40)	0.225	2.07 (1.20–3.56)	0.009	0.89 (0.48–1.65)	0.720

Abbreviations: ADC, adenocarcinoma; CEA, carcinoembryonic antigen; DFS, disease-free survival; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.

Figure S1 Five types of tumor–pleural surface relationship.

Notes: (A) No contacting, (B) abutting pleural, (C) pleural tag type I, (D) pleural tag type II, and (E) pleural tag type III. The red arrows illustrate the five types of tumor–pleural surface relationship on CT images.

Table S1 Association analysis between EGFR mutations and clinicopathologic characteristics

Characteristics	Total	EGFR wild- type		EGFR mutant		χ^2	P-value	Univariate analysis
		n	%	n	%			OR (95%CI)	P-value
	508	265	52.2	243	47.8
Age, years (mean ± SD)		60.82±10.21		61.82±9.05			0.241a	1.01 (0.99–1.03)	0.243
<60	215	120	45.3	95	39.1	1.99	0.158
≥60	293	145	54.7	148	60.9
Gender						35.01	<0.001
Male	264	171	64.5	93	38.3			1.00 (reference)
Female	244	94	35.5	150	61.7			2.93 (2.05–4.21)	<0.001
Smoking status						33.36	<0.001
Ever	198	135	50.9	63	25.9			1.00 (reference)
Never	310	130	49.1	180	74.1			2.97 (2.04–4.32)	<0.001
Tumor size, mm (mean ± SD)		29.90±16.23		24.47±12.92			<0.001a	0.97 (0.96–0.99)	<0.001
≤30	356	164	61.9	192	79	18.36	<0.001	1.00 (reference)
30–50	116	75	28.3	41	16.9			0.47 (0.30–0.72)	0.001
>50	36	26	9.8	10	4.1			0.33 (0.15–0.70)	0.004
Trend								0.52 (0.39–0.71)	<0.001
Nodule type						24.96	<0.001
Non-solid	114	36	13.6	78	32.1			1.00 (reference)
Solid	394	229	86.4	165	67.9			0.33 (0.21–0.52)	<0.001
pTNM stage						2.19	0.335
I	343	173	65.3	170	70			1.00 (reference)
II	54	33	12.5	21	8.6			0.65 (0.36–1.16)	0.147
III	111	59	22.3	52	21.4			0.90 (0.58–1.38)	0.619
Trend
Histological type						77.71	<0.001
ADC	411	176	66.4	235	96.7			1.00 (reference)
SCC	82	78	29.4	4	1.6			0.04 (0.01–0.11)	<0.001
Othersb	15	11	4.2	4	1.6			0.27 (0.09–0.87)	0.028
VPI						25.81	<0.001
No	279	174	65.7	105	43.2			1.00 (reference)
Yes	229	91	34.3	138	56.8			2.51 (1.76–3.60)	<0.001
Preoperative CEA (ng/mL)	499c					1.47	0.225
<5	378	202	78	176	73.3			1.00 (reference)
≥5	121	57	22	64	26.7			1.29 (0.86–1.94)	0.226
Lymphatic metastasis						2.17	0.338
N0	393	208	78.5	185	76.1			1.00 (reference)
N1	24	9	3.4	15	6.2			1.87 (0.80–4.38)	0.147
N2	91	48	18.1	43	17.7			1.01 (0.64–1.59)	0.975
Trend								1.03 (0.83–1.29)	0.778
Tumor–pleural relationship						15.62	0.004
No contacting	147	95	35.8	52	21.4			1.00 (reference)
Pleural tag type I	69	33	12.5	36	14.8			1.99 (1.12–3.56)	0.02
Pleural tag type II	99	40	15.1	59	24.3			2.70 (1.59–4.56)	<0.001
Pleural tag type III	30	14	5.3	16	6.6			2.09 (0.95–4.61)	0.069
Abutting pleural	163	83	31.3	80	32.9			1.76 (1.12–2.78)	0.015
Trend								1.13 (1.01–1.25)	0.032

Notes:

a P-value for independent t-test.

b Other histological types including large cell lung cancer and adenosquamous carcinoma.

c A total of 499 patients underwent preoperative CEA examination in this study.

Abbreviations: ADC, adenocarcinoma; CEA, carcinoembryonic antigen; pTNM, pathological TNM; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.

Table S2 Association analysis between EGFR 19-del and clinicopathologic characteristics

Characteristics	Total	EGFR wild-type			EGFR 19-del		P-value	Univariate analysis
		n		%	n	%		OR (95%CI)	P-value
	508	265		52.2
Age, years (mean ± SD)		60.82±10.21			60.36±9.68		0.92a	0.99 (0.97–1.02)	0.703
<60	215	120		45.3	43	43.4	0.752
≥60	293	145		54.7	56	56.6
Gender							<0.001
Male	264	171		64.5	35	35.4		1.00 (reference)
Female	244	94		35.5	64	64.6		3.33 (2.05–5.39)	<0.001
Smoking status							<0.001
Ever	198	135		50.9	26	26.3		1.00 (reference)
Never	310	130		49.1	73	73.7		2.92 (1.75–4.85)	<0.001
Tumor size, mm (mean ± SD)		29.90±16.23			24.00±12.84		0.001a	0.97 (0.96–0.99)	0.002
≤30	356	164	61.9		78	78.8	0.008	1.00 (reference)
30–50	116	75	28.3		17	17.2		0.48 (0.26–0.86)	0.014
>50	36	26	9.8		4	4		0.32 (0.11–0.96)	0.042
Trend								0.52 (0.34–0.81)	0.003
Nodule type							0.001
Non-solid	114	36	13.6		28	28.3		1.00 (reference)
Solid	394	229	86.4		71	71.7		0.40 (0.23–0.70)	0.001
pTNM stage							0.933
I	343	173	65.3		65	65.7		1.00 (reference)
II	54	33	12.5		11	11.1		0.89 (0.42–1.86)	0.751
III	111	59	22.3		23	23.2		1.04 (0.59–1.82)	0.897
Trend								1.01 (0.77–1.33)	0.952
Histological type							<0.001
ADC	411	176	66.4		97	98		1.00 (reference)
SCC	82	78	29.4		1	1		0.02 (0.01–0.17)	<0.001
Othersb	15	11	4.2		1	1		0.17 (0.02–1.30)	0.087
VPI							<0.001
No	279	174	65.7		41	41.4		1.00 (reference)
Yes	229	91	34.3		58	58.6		2.71 (1.69–4.34)	<0.001
Preoperative CEA (ng/mL)	499c						0.617
<5	378	202	78		74	75.5		1.00 (reference)
≥5	121	57	22		24	24.5		1.15 (0.67–1.99)	0.617
Lymphatic metastasis							0.102
N0	393	208	78.5		73	73.7		1.00 (reference)
N1	24	9	3.4		9	9.1		2.85 (1.09–7.45)	0.033
N2	91	48	18.1		17	17.2		1.01 (0.55–1.87)	0.977
Trend								1.07 (0.79–1.43)	0.676
Tumor–pleural relationship							0.018
No contacting	147	95	35.8		18	18.2		1.00 (reference)
Pleural tag type I	69	33	12.5		14	14.1		2.24 (1.01–5.00)	0.049
Pleural tag type II	99	40	15.1		24	24.2		3.17 (1.55–6.47)	0.002
Pleural tag type III	30	14	5.3		5	5.1		2.42 (1.28–4.55)	0.275
Abutting pleural	163	83	31.3		38	38.4		2.42 (1.28–4.55)	0.006
Trend								1.19 (1.03–1.37)	0.016

Notes:

a P-value for independent t-test.

b Other histological types including large cell lung cancer and adenosquamous carcinoma.

c A total of 499 patients underwent preoperative CEA examination in this study.

Abbreviations: ADC , adenocarcinoma; CEA, carcinoembryonic antigen; pTNM, pathological TNM; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.

Table S3 Association analysis between EGFR L858R and clinicopathologic characteristics

Characteristics	Total	EGFR wild-type		EGFR L858R		P-value	Univariate analysis
		n	%	n	%		OR (95%CI)	P-value
	508	265	52.2
Age, years (mean ± SD)		60.82±10.21		62.58±8.47		0.177a	1.02 (0.99–1.04)	0.097
<60	215	120	45.3	44	36.1	0.088
≥60	293	145	54.7	78	63.9
Gender						<0.001
Male	264	171	64.5	45	36.9		1.00 (reference)
Female	244	94	35.5	77	63.1		3.11 (1.99–4.86)	<0.001
Smoking status						<0.001
Ever	198	135	50.9	30	24.6		1.00 (reference)
Never	310	130	49.1	92	75.4		3.19 (1.98–5.13)	<0.001
Tumor size, mm (mean ± SD)		29.90±16.23		23.99±12.62		<0.001a	0.97 (0.96–0.99)	0.001
≤30	356	164	61.9	100	82	<0.001	1.00 (reference)
30–50	116	75	28.3	19	15.6		0.42 (0.24–0.73)	0.002
>50	36	26	9.8	3	2.5		0.19 (0.06–0.64)	0.008
Trend							0.42 (0.28–0.66)	<0.001
Nodule type						<0.001
Non-solid	114	36	13.6	44	36.1		1.00 (reference)
Solid	394	229	86.4	78	63.9		0.28 (0.17–0.46)	<0.001
pTNM stage						0.06
I	343	173	65.3	90	73.8		1.00 (reference)
II	54	33	12.5	6	4.9		0.35 (0.14–0.87)	0.023
III	111	59	22.3	26	21.3		0.85 (0.50–1.44)	0.537
Trend							0.87 (0.67–1.13)	0.299
Histological type						<0.001
ADC	411	176	66.4	118	96.7		1.00 (reference)
SCC	82	78	29.4	1	0.8		0.02 (0.01–0.14)	<0.001
Othersb	15	11	4.2	3	2.5		0.41 (0.11–1.49)	0.174
VPI						<0.001
No	279	174	65.7	54	44.3		1.00 (reference)
Yes	229	91	34.3	68	55.7		2.41 (1.55–3.73)	<0.001
Preoperative CEA (ng/mL)	499c					0.341
<5	378	202	78	89	73.6		1.00 (reference)
≥5	121	57	22	32	26.4		1.27 (0.77–2.10)	0.342
Lymphatic metastasis						0.902
N0	393	208	78.5	94	77		1.00 (reference)
N1	24	9	3.4	5	4.1		1.23 (0.40–3.77)	0.718
N2	91	48	18.1	23	18.9		1.06 (0.61–1.84)	0.836
Trend							1.04 (0.79–1.36)	0.789
Tumor–pleural relationship						0.054
No contacting	147	95	35.8	28	23		1.00 (reference)
Pleural tag type I	69	33	12.5	21	17.2		2.16 (1.08–4.31)	0.029
Pleural tag type II	99	40	15.1	29	23.8		2.46 (1.30–4.65)	0.006
Pleural tag type III	30	14	5.3	7	5.7		1.51 (0.85–2.68)	0.3
Abutting pleural	163	83	31.3	37	30.3		1.51 (0.85–2.68)	0.157
Trend							1.08 (0.94–1.23)	0.278

Notes:

a P-value for independent t-test.

b Other histological types including large cell lung cancer and adenosquamous carcinoma.

c A total of 499 patients underwent preoperative CEA examination in this study.

Abbreviations: ADC, adenocarcinoma; CEA, carcinoembryonic antigen; pTNM, pathological TNM; SCC, squamous cell carcinoma; VPI, visceral pleural invasion.