Table 6.

Predictive Factors for Tumor Necrosis in Osteosarcoma at 50% Cutoff

Predictive Factors	> 50% Necrosis (%) (n=30)	≤ 50% Necrosis (%) (n=10)	p value
Tumor change in size			p = 0.03*
Larger	6 (20)	3 (30)
Smaller	13 (43)	0 (0)
No change	11 (37)	7 (70)
Post-chemo tumor size			p = 0.72
> 10 cm	10 (33)	4 (40)
≤ 10 cm	20 (67)	6 (60)
Post-chemo pain			p < 0.01*
Yes	8 (27)	8 (80)
No	22 (73)	2 (20)
Post-chemo ossification			p = 0.03*
Increase	26 (87)	5 (50)
No Increase	4 (13)	5 (50)

*Proportions between the two groups are compared using Chi-square test or Fischer exact, p value of ≤ 0.05 is significant.