Table 1.

Characteristics of osteosarcoma patients and control subjects

Variables	Patients	%	Controls	%	χ2 value	P value
Age, years
< 20	94	61.84	182	59.87
≥ 20	58	38.16	122	40.13	0.17	0.68
Gender
Female	64	42.11	128	42.11
Male	88	57.89	176	57.89	0.00	1.00
Enneking stage
I-II	97	63.82
III	55	36.18
Tumor location
Extremities	110	72.37
Other	42	27.63
Tumor metastasis
Negative	94	61.84
Positive	58	38.16