Radiation Induced
Secondary osteogenic sarcomas (OS) were originally seen in patients with Ewings sarcoma who had received high doses of orthovoltage radiation therapy (RT) to treat their primary tumor. The dose was significantly magnified in bone with orthovoltage RT.
OS are also associated with megavoltage RT, but the risk is much lower.
The interval between the therapeutic RT and the appearance of the secondary OS can be between 4 and 40 years later (median is 12 to 15 years later).
Secondary OS have occurred after RT for both benign and malignant lesions.
Bilateral retinoblastoma significantly increases the risk of secondary OS within the previous RT field.
Chemotherapy Associated
Treatment with alkylating agents is also associated with a risk of secondary OS (independent of any RT). Risk of OS increases with increasing exposure to drug.
Therapy
A single-institution retrospective review has reported that patients with osteosarcoma arising following RT treated with multiagent chemotherapy and surgical resection have a prognosis similar to patients with osteosarcoma arising de novo.
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