Table 2:

Clinical characteristics of the squamous cell carcinoma group patients before and after matching of propensity score (%)

Characteristics	Before PSM			After PSM
	Preoperative radiotherapy group (n = 97)	Surgery alone group (n = 310)	SMD	Preoperative radiotherapy group (n = 85)	Surgery alone group (n = 82)	SMD
Age(years), n (%)			0.422			0.103
≤66	64 (66.0)	141 (45.5)		53 (62.4)	47 (57.3)
>66	33 (34.0)	169 (54.5)		32 (37.6)	35 (42.7)
Race, n (%)			0.134			0.172
Black	12 (12.4)	31 (10.0)		10 (11.8)	7 (8.5)
White	80 (82.5)	254 (81.9)		70 (82.3)	67 (81.7)
Others	5 (5.1)	25 (8.1)		5 (5.9)	8 (9.8)
Gender, n (%)			0.081			0.128
Male	69 (71.1)	209 (67.4)		61 (71.8)	54 (65.9)
Female	28 (28.9)	101 (32.6)		24 (28.2)	28 (34.1)
Grade, n (%)			0.301			0.401
I	0 (0.0)	8 (2.6)		0 (0.0)	2 (2.4)
II	37 (38.1)	133 (42.9)		37 (43.5)	25 (30.5)
III	60 (61.9)	166 (53.5)		48 (56.5)	53 (64.6)
IV	0 (0.0)	3 (1.0)		0 (0.0)	2 (2.4)
Laterality, n (%)			0.343			0.153
Left	35 (36.1)	164 (52.9)		35 (41.2)	40 (48.8)
Right	62 (63.9)	146 (47.1)		50 (58.8)	42 (51.2)
Stage, n (%)			0.146			0.015
IIIA	83 (85.6)	280 (90.3)		73 (85.9)	70 (85.4)
IIIB	14 (14.4)	30 (9.7)		12 (14.1)	12 (14.6)
Tumour stage, n (%)			0.360			0.262
T1	6 (6.2)	47 (15.2)		5 (5.9)	11 (13.4)
T2	44 (45.4)	155 (50.0)		44 (51.8)	38 (46.3)
T3	33 (34.0)	78 (25.2)		24 (28.2)	21 (25.6)
T4	14 (14.4)	30 (9.7)		12 (14.1)	12 (14.6)
LN examined, n (%)			0.264			0.096
0–9	43 (44.3)	98 (31.6)		34 (40.0)	29 (35.4)
≥10	54 (55.7)	212 (68.4)		51 (60.0)	53 (64.6)
LN positivity, n (%)			0.045			0.017
0–5	79 (81.4)	247 (79.7)		71 (83.5)	69 (84.1)
≥6	18 (18.6)	63 (20.3)		14 (16.5)	13 (15.9)

LN: lymph node; PSM: propensity score matching; SMD: standard mean difference.