Risk Analysis of Distal Metastasis in Chondrosarcoma and the Development and Validation of a Novel Clinical Prediction Model: A Clinical Study Based on the SEER Database

Table 3

Baseline data table of the training group and the validation group.

Variable	Level	Overall (N = 1290)	Training group (N = 906)	Validation group (N = 384)
Race (%)	Black	96 (7.44)	65 (7.17)	31 (8.07)	0.6624
	Other	77 (5.97)	57 (6.29)	20 (5.21)
	White	1117 (86.59)	784 (86.53)	333 (86.72)
Age (median (IQR))	NA	54.000 [41.000, 67.000]	54.000 [41.000, 67.000]	55.000 [41.000, 67.000]	0.6463
Sex (%)	Female	571 (44.26)	401 (44.26)	170 (44.27)	1
	Male	719 (55.74)	505 (55.74)	214 (55.73)
Primary site (%)	Axis bone	677 (52.48)	471 (51.99)	206 (53.65)	0.6012
	Bone of limb	544 (42.17)	383 (42.27)	161 (41.93)
	Other	69 (5.35)	52 (5.74)	17 (4.43)
Laterality (%)	Left	496 (38.45)	353 (38.96)	143 (37.24)	0.6818
	Not a paired site	293 (22.71)	200 (22.08)	93 (24.22)
	Right	501 (38.84)	353 (38.96)	148 (38.54)
Grade (%)	Moderately differentiated; grade II	518 (40.16)	346 (38.19)	172 (44.79)	0.1098
	Poorly differentiated; grade III	129 (10.00)	99 (10.93)	30 (7.81)
	Undifferentiated; anaplastic; grade IV	39 (3.02)	28 (3.09)	11 (2.86)
	Unknown	169 (13.10)	127 (14.02)	42 (10.94)
	Well differentiated; grade I	435 (33.72)	306 (33.77)	129 (33.59)
T (%)	T1	716 (55.50)	503 (55.52)	213 (55.47)	0.8912
	T2	389 (30.16)	272 (30.02)	117 (30.47)
	T3	13 (1.01)	8 (0.88)	5 (1.30)
	TX	172 (13.33)	123 (13.58)	49 (12.76)
N (%)	N0	1237 (95.89)	869 (95.92)	368 (95.83)	0.6182
	N1	11 (0.85)	9 (0.99)	2 (0.52)
	NX	42 (3.26)	28 (3.09)	14 (3.65)
M (%)	M0	1215 (94.19)	853 (94.15)	362 (94.27)	1
	M1	75 (5.81)	53 (5.85)	22 (5.73)
Surgery (%)	No	177 (13.72)	124 (13.69)	53 (13.80)	1
	Yes	1113 (86.28)	782 (86.31)	331 (86.20)
Lymph node dissection (%)	No	1213 (94.03)	854 (94.26)	359 (93.49)	0.6848
	Yes	77 (5.97)	52 (5.74)	25 (6.51)
Radiation (%)	No	1149 (89.07)	807 (89.07)	342 (89.06)	1
	Yes	141 (10.93)	99 (10.93)	42 (10.94)
Chemotherapy (%)	No/unknown	1231 (95.43)	859 (94.81)	372 (96.88)	0.14
	Yes	59 (4.57)	47 (5.19)	12 (3.12)
Survival months (median (IQR))	NA	31.000 [13.000, 53.000]	31.000 [13.000, 54.000]	30.500 [13.000, 51.000]	0.2844