Table 2.

Clinical data.

Variable	Category	N	(%)
Histological type	Adenocarcinoma	115	65
	Squamous cell carcinoma	57	32.2
	Other	5	2.8
Tumor grade	Grade I	5	2.8
	Grade II	81	45.8
	Grade III	50	28.2
	Ignored	41	23.2
TNM staging	I	62	35
	II	53	29.9
	III	43	24.3
	IV	19	10.7
Surgery type	Nodule extraction	4	2.3
	Segmentectomy	12	6.8
	Lobectomy	147	83.1
	Pneumonectomy	14	7.9
Systemic treatment	No	121	68.4
	Yes	55	31
	Neoadjuvant chemotherapy	21	11.9
	Adjuvant chemotherapy	34	19.2
	Chemotherapy + radiotherapy	3	1.7
	Ignored	1	0.6
Adjuvant radiotherapy	Yes	23	13
	No	154	87

TNM staging: TNM Classification of Malignant Tumours.