The Time of the Insult/Triggering Event in Primary Osteosarcoma and Ewing’s Sarcoma of Bone as Determined by Incubation Period Modeling and Age Distribution of Such Malignancies

Table 1

Demographics for conventional and parosteal osteosarcoma.

Variable	Total	Conventional	%	Parosteal	%	value
Average age (yrs)	28.0 ± 20.3	28.1 ± 20.8	—	28.4 ± 13.0	—	<0.0001
Median age (yrs)	19	19		26
Geographic location in the USA
Midwest	727	679	17.0	48	21.3	0.39
Northeast	553	526	13.2	27	12.0
South	589	561	14.1	28	12.4
West	2344	2222	55.7	122	54.2
Sex
Male	2338	2235	56.0	103	45.8	0.003
Female	1875	1753	44.0	122	54.2
Race
White	3217	3051	77.3	166	75.1	0.28
Black	607	568	14.4	39	17.6
Indo-Malay	247	238	6.0	9	4.1
Amerindian	37	34	0.9	3	1.4
Indo-Mediterranean	25	22	0.6	3	1.4
Polynesian	37	36	0.9	1	0.5
Primary site
Long bone	3142	2942	75.2	200	88.9	<0.0001
Short bone	98	90	2.3	8	3.6
Mandible	179	175	4.5	4	1.8
Pelvis	316	316	8.1	0	0.0
RSTCl	89	83	2.1	6	2.7
Skull	215	209	5.3	6	2.7
Vertebral	98	98	2.5	1	0.4

RSTCl: rib, sternum, clavicle.