Whether the cancer is localized, metastatic, or recurrent
How long the patient has had symptoms
The patient's blood test results (and other test results)
How much of the cancer is taken out by surgery or killed by chemotherapy
The patient's age and general health.
(Click Bone Cancer Prognosis for an in-depth discussion about the prognosis of osteosarcoma and other bone cancers. This article discusses what determines a prognosis and how the factors explained above influence statistics regarding survival.)