Causes and risk factors The cause of most bone<unk> s is not known, but several factors are associated with an increased risk of developing bone<unk> . Previous exposure to ionizing radiation (such as prior radiation therapy) is one such risk factor. Exposure to alkylating agents, such as those found in certain cancer chemotherapeutic medicines, also increases the risk of bone<unk> . Certain inherited genetic syndromes, including Li-Fraumeni syndrome, heritable RB1 gene mutations, and Paget's disease of bone, are associated with an increased risk of developing bone<unk> s. Most soft tissue<unk> s arise from what doctors call "sporadic" (or random) genetic mutations within an affected person's cells. Nevertheless, there are certain risk factors associated with an increased risk of developing soft tissue<unk> . Previous exposure to ionizing radiation is one such risk factor. Exposure to vinyl chloride (e.g., such as the fumes encountered in the production of Polyvinyl chloride (PVC)), Arsenic and Thorotrast all are associated with an increased risk of angiosarcoma. Lymphedema, such as that resulting from certain types of breast cancer treatment, also is a risk factor for development of angiosarcoma. As with bone<unk> s, certain inherited genetic syndromes also are associated with an increased risk of developing soft tissue<unk> , including Li-Fraumeni syndrome, familial adenomatous polyposis, neurofibromatosis type 1, and heritable RB1 gene mutations. Kaposi's<unk>  is caused by Kaposi's<unk> -associated herpesvirus (HHV-8).
Sarcoma
Angiosarcoma
Soft-tissue sarcoma
Hemangiosarcoma
Xanthoma
Myosarcoma
Epithelioma
Liposarcoma