Table-I.

Characteristics of patients with osteosarcoma and controls.

Characteristics	Cases	%	Controls	%	OR(95%CI)	P value
Gender
Male	91	61.49	181	61.15	1.0(Ref.)
Female	57	38.51	115	38.85	0.98(0.64-1.51)	0.95
Mean age, years	17.7±8.2		19.2±5.3
<20	87	58.78	164	55.41	1.0(Ref.)
≥20	61	41.22	132	44.59	0.87(0.57-1.32)	0.5
Family history of cancer
Positive	35	23.65	63	21.28	1.0(Ref.)
Negative	113	76.35	233	78.72	0.87(0.53-1.44)	0.57
Stage
I-II	106	71.62
III	42	28.38
Histological type
Osteoblastic	48	32.43
Chondroblastic	70	47.3
Other	30	20.27
Tumor location
Extremities	107	72.3
Other	41	27.7