TABLE 4.

Univariate results derived from the log-rank test used to evaluate the development of local recurrence and survival over a 10-year period following resection

Variable	Local Recurrence*			Survival
	No. of Patients	No. of Observed Events (recurrences)	p Value	No. of Patients	No. of Observed Events (deaths)	p Value
Age at surgery (yrs)
<55	50	14	0.201	52	15	0.335
55–64	54	21		56	19
≥65	58	19		58	22
Diagnostic method
Open biopsy	29	7	0.197	29	9	0.439
CT-trocar biopsy	76	24		76	27
Intraoperative biopsy	19	8		21	11
Spinal location
Cervical	53	16	0.138	54	20	0.137
Thoracic	24	9		24	9
Lumbar	75	26		78	26
No. of vertebral levels spanned by the tumor
1	96	37	0.541	97	32	0.027
≥2	66	17		69	24
Tumor grade
Low (Grade I)	93	33	0.245	94	27	0.622
High (Grade II)	53	16		56	23
Tumor vol ellipsoid body (cm3)†
<20	41	14	0.589	42	14	0.579
20–59	39	12		40	16
≥60	37	7		37	7
Pathological results of the surgical specimen
Intralesional	67	34	<0.001	68	26	0.060
Marginal or wide	71	11		72	17
Enneking appropriateness
EA	57	8	<0.001	58	13	0.023
EI	83	38		84	32
Adjuvant therapy
No	81	22	0.006	81	22	0.024
Yes	77	29		81	31

^*Complete information is available for 162 of 166 patients.

^†Tumor volume ellipsoid body = π/6 × height × width × depth.