Table I. Establishment frequency of the patient breast osteosarcoma in nude mice.

The surgical specimen of the patient breast osteosarcoma was minced into fragments of approximately 2 mm³ (Figure 1). The fragments were inserted into a subcutaneous pocket made in nude mice. Mice were observed for tumor formation starting on day 14 after implantation. By day 28, 90.2% of mice implanted had observable tumor growth.