Table 3.

Cox model for event-free survival (timed from diagnostic biopsy) for all ‘registration cohort’ patients, N = 1867.

Characteristic	N	EFS events	Adjusted HR (95% CI)	p-value	Overall p-value
Pulmonary metastases
No metastasesa	1633	607	1.00	n/a	<0.001
Metastases	234	155	2.34 (1.95–2.81)	<0.001
Other metastases
No metastases	1809	724	1.00	n/a	<0.001
Metastases	58	38	1.94 (1.38–2.73)	<0.001
Site of the tumour
Other limb site	1562	596	1.00	n/a	<0.001
Proximal femur/humerus	234	124	1.50 (1.22–1.84)	<0.001
Axial skeleton	71	42	1.53 (1.10–2.13)	0.011
WHO classification of sarcoma at diagnosis
Conventional: chondroblastic	300	144	1.00	n/a	0.002
Conventional: osteoblastic	1154	484	0.85 (0.71–1.03)	0.101
Conventional: other	293	99	0.67 (0.52–0.88)	0.003
Telangiectatic	86	24	0.52 (0.33–0.80)	0.003
Small cell	10	5	1.48 (0.60–3.64)	0.389
High-grade surface	24	6	0.44 (0.19–0.99)	0.047
Age
Child	557	201	1.00	n/a	0.015
Adolescent	921	388	1.25 (1.05–1.48)	0.013
Adult	389	173	1.32 (1.07–1.63)	0.008
Gender
Female	761	288	1.00	n/a	0.017
Male	1106	474	1.20 (1.03–1.39)	0.017
Relative tumour volumeb
Small (<1/3 of involved bone)	851	307	1.00	n/a	0.002
Large (≥1/3 of involved bone)	680	333	1.29 (1.09–1.51)	0.002
Pathological fracture at diagnosis
No	1645	669	1.00	n/a	0.966
Yes	222	93	1.00 (0.80–1.26)	0.966
Surgical margins achievedc
Wide/Radical	1593	636	1.00	n/a	0.262
Marginal	249	110	1.03 (0.82–1.30)	0.797
Intralesional	25	16	1.54 (0.92–2.59)	0.102

CI, confidence interval; EFS, event-free survival; HR, hazard ratio; WHO, World Health Organisation.

^aincludes possible metastases.

^b336 missing values imputed.

^cas reported by the pathologist.