Ewing's sarcoma is a malignant (cancerous) bone tumor that affects children. Ewing's sarcoma can occur any time during childhood and young adulthood, but usually develops during puberty, when bones are growing rapidly. The tumor often spreads (metastasis) to the lungs and other bones. Metastasis at the time of diagnosis is present in approximately one third of children with Ewing's sarcoma. Ewing's sarcoma only rarely occurs in adults and never over 50 years of age.

Osteosarcoma is a cancerous tumor that occurs in the bone. Osteosarcoma is a primary bone cancer. That means the cancer originates in the bone itself.

Most osteosarcomas appear in the long bones of the body, such as the femur (the thigh bone), the tibia (the shinbone) or the humerus (the bone that runs from the shoulder to the elbow), although they can appear in any bones.

Osteosarcoma is the oldest cancer known to man. A fossilized humanoid foot found in South Africa is 1.7m years old and it had osteosarcoma.

Adjuvant treatment is a kind of "preventative therapy": After the complete removal of a tumor, adjuvant treatment is given as prophylaxis against recurrences. It aims to treat so called micro metastases that may be present but not yet visible, and therefore lower the risk of a recurrence. Adjuvant therapy is usually recommended for sarcoma patients, whose risk of recurrence – despite a successful operation – remains high.

Gastrointestinal stromal tumor (GIST) affects the digestive tract or nearby structures within the abdomen. The most common location is the stomach. GI stromal tumor, or GIST cancer, is a sarcoma.