Table 1.

Grading^a of lung metastasis of OSA-bearing animals

Groups	Timeb	Drug	Metastasis grade	Mean ± SD	Metastasis rate
Group A	42 days	Collagen gel	1, 2, 2, 3, 4	2.4±1.14 (n=5)	5/5
Group B	56 days	Collagen gel	3, 4, 4, 4, 4	3.8±0.45 (n=5)	5/5
Group C	42 days	rhBMP-2	1, 1, 2, 3, 3	2.0±1.0 (n=5)	5/5
Group D	56 days	rhBMP-2	0, 2, 2, 3, 4	2.2±1.48 (n=5)	4/5

Notes:

^aGrading criteria based on the coverage of tumor cell aggregation over the sectioned lung tissue. Relatively normal, 0% =0; mild, <25% =1; moderate, 25%–50% =2; moderate to marked, 50%–75% =3; marked, >75% =4.

^bDays after the inoculation of human OSA 143B cells.

Abbreviations: OSA, osteosarcoma; rhBMP-2, recombinant human BMP-2.