A Novel Tool to Predict the Overall Survival of High-Grade Osteosarcoma Patients after Neoadjuvant Chemotherapy: A Large Population-Based Cohort Study

Table 1

Clinical and pathological characteristics of high-grade osteosarcoma patients after neoadjuvant chemotherapy.

Variables	Total cohort		Training cohort		Validation cohort
	N = 762		N = 534		N = 228
	n	%	n	%	n	%
Age
<16	409	53.7	289	54.1	120	52.6
16–21	194	25.5	136	25.5	58	25.4
>21	159	20.9	109	20.4	50	21.9
Race
Black	124	16.3	89	16.7	35	15.4
White	568	74.4	401	75.1	167	73.2
Others	79	10.4	44	8.2	26	11.4
Sex
Male	431	56.6	303	56.7	128	56.1
Female	331	43.3	231	43.3	100	43.9
Primary site
Upper limb	114	15.0	77	14.4	37	16.2
Lower limb	613	80.4	436	81.6	177	77.6
Others	35	4.6	21	3.9	14	6.1
Grade
III	266	34.9	191	35.8	75	32.9
IV	496	65.1	343	64.2	153	67.1
Laterality
Left—origin of primary	389	51.0	263	49.3	126	55.3
Right—origin of primary	373	49.0	271	50.7	102	44.7
Radiotherapy
No	742	97.4	519	97.2	223	97.8
Yes	20	2.6	15	2.8	5	2.2
Postoperative chemotherapy
No	279	36.6	192	36.0	87	38.2
Yes	483	63.4	342	64.0	141	61.8
Disease stage
Localized	226	29.7	147	27.5	79	34.6
Regional	378	49.6	276	51.7	102	44.7
Distant	158	20.7	111	20.8	47	20.6
Tumor size
<64	110	14.4	79	14.8	31	13.6
64–139	465	61.0	327	61.2	138	60.5
>139	187	24.5	128	24.0	59	25.9
Marital status
Unmarried	689	90.4	481	90.0	208	91.2
Married	73	9.6	53	10.0	20	8.8