Epigenetic imprinting alterations as effective diagnostic biomarkers for early-stage lung cancer and small pulmonary nodules

Table 1 Baseline characteristics of study population

	Model building set (n = 246)				Model testing set (n = 30)			Model validation set (n = 155)
	Normal^a	Benign	Malignant	p	Benign	Malignant	p	Benign	Malignant	p
	(n = 21)	(n = 51)	(n = 174)	p	(n = 9)	(n = 21)	p	(n = 38)	(n = 117)	p
Age				< 0.001			0.700			0.001
Median	52	57	62		62	62		61	64
IQR	45–57	49–63	53–67		49–77	56–66		52–63	58–71
Sex (%)				0.467			0.640			0.692
Male	14 (66.7%)	28 (54.9%)	111 (63.8%)		6 (66.7%)	17 (81.0%)		25 (65.8%)	81 (69.2%)
Female	7 (33.3%)	23 (45.1%)	63 (36.2%)		3 (33.3%)	4 (19.0%)		13 (34.2%)	36 (30.8%)
Sample type
Surgically resected tissue specimen	21	51	174
Small biopsy specimen					9	21		38	36
Cytology specimen									81
Histologic characteristics no
Normal	21
PC		10
PSP		13
TB		10			2			7
COP		10						2
PIP		3
Non-TB infections					3			8
Inflammation		3			4			19
Granuloma		2						1
Hamartoma								1
AdC			94			9			61
SqCC			76			6			28
AdSqLC			2						2
LCC			1
SCLC						5			23
Carcinoma of unknown primary			1			1			3
Nodule size				^e			^e			^e
< 0.8 cm			7		2			10	1
≥ 0.8–2.0 cm		3	35		1	1		2	20
> 2.0–3.0 cm			48			9		3	32
> 3.0–5.0 cm		1	52			4		4	42
> 5.0 cm			28			6			18
Unclear LDCT features^b	21	44			5			12	1
Not specified^c		3	4		1	1		7	3
Smoking status^d (%)				0.001			^e			0.006
Current smoker	3 (14.3%)	3 (5.9%)	56 (32.2%)		1 (11.1%)	6 (28.6%)		7 (18.4%)	48 (41.0%)
Former smoker	1 (4.8%)	1 (2.0%)	11 (6.3%)		0 (0.0%)	3 (14.3%)		2 (5.3%)	11 (9.4%)
Non-smoker	15 (71.4%)	40 (78.4%)	90 (51.7%)		1 (11.1%)	8 (38.1%)		16 (42.1%)	40 (34.2%)
Not specified	2 (9.5%)	7 (13.7%)	17 (9.8%)		7 (77.8%)	4 (19.0%)		13 (34.2%)	18 (15.4%)

PC, Pulmonary cryptococcosis. PSP, pulmonary sclerosing pneumocytoma. TB, pulmonary tuberculosis. COP, cryptogenic organizing pneumonia. PIP, pulmonary inflammatory pseudotumor. AdC, adenocarcinoma. SqCC, squamous cell carcinoma. AdSqLC, adenosquamous lung carcinoma. LCC, large cell carcinoma. SCLC, small cell lung cancer
^aNormal tissue specimens were resected adjacent to the benign lesions
^bNo typical nodule under LDCT
^cNodule sizes not recorded by doctors
^dCases classified as current or former smokers were combined into a single category prior to analysis to comply with the statistical test requirements
^eNo analysis proceeded since data transformations applied failed to meet the statistical test requirements

ISSN: 1868-7083