Table 1. Patient characteristics.

Variable	Category	Total	Relapsed	Relapse-free	P-value
Training set – SCC
		n=50 (100%)	n=20 (100%)	n=30 (100%)
Sex	Male	39 (78)	17 (85)	22 (73)	0.53
	Female	11 (22)	3 (15)	8 (27)
Stage	IA	6 (12)	0 (0)	6 (20)	0.08
	IB	25 (50)	11 (55)	14 (47)
	IIA	0 (0)	0 (0)	0 (0)
	IIB	17 (34)	9 (45)	8 (27)
	IIIA	2 (4)	0 (0)	2 (7)
Grade	G1	4 (8)	2 (10)	2 (7)	0.65
	G2	34 (68)	12 (60)	22 (73)
	G3	12 (24)	6 (30)	6 (20)
Mean age (range)		67 (48–77)	63 (48–75)	68 (49–77)	0.38
Confirmatory set – SCC
		n=134 (100%)	n=54 (100%)	n=80 (100%)
Sex	Male	101 (75)	39 (72)	62 (77)	0.55
	Female	33 (25)	15 (28)	18 (23)
Stage	IA	29 (22)	5 (9)	24 (30)	0.034
	IB	65 (48)	25 (46)	40 (50)
	IIA	4 (3)	1 (2)	3 (4)
	IIB	31 (23)	20 (37)	11 (14)
	IIIA	5 (4)	3 (6)	2 (2)
Grade	G1	5 (4)	2 (4)	3 (4)	0.52
	G2	78 (58)	29 (54)	49 (61)
	G3	51 (38)	23 (42)	28 (35)
Mean age (range)		64 (39–81)	62 (39–79)	64 (47–81)	0.033
AC
		n=89 (100%)	n=35 (100%)	n=54 (100%)
Sex	Male	57 (64)	24 (69)	33 (61)	0.62
	Female	32 (36)	11 (31)	21 (39)
Stage	IA	28 (31)	7 (20)	21 (39)	0.093
	IB	34 (38)	12 (34)	22 (41)
	IIA	3 (3)	2 (6)	1 (2)
	IIB	23 (26)	13 (37)	10 (18)
	IIIA	1 (1)	1 (3)	0 (0)
Predominant histological type	Acinar	34 (38)	18 (51)	16 (30)	0.31
	Solid	30 (34)	10 (29)	20 (37)
	Papillary	7 (8)	3 (8)	4 (7)
	Micro-papillary	3 (3)	1 (3)	2 (4)
	Lepidic	8 (9)	1 (3)	7 (13)
	Mucinous	7 (8)	2 (6)	5 (9)
Mean age (range)		61 (45–81)	61 (45–81)	61 (46–75)	0.46

Abbreviations: AC=adenocarcinoma; SCC=squamous cell carcinoma.