Osteosarcoma is the most common type of primary bone cancer, making up 35 percent of bone cancer cases. This cancer affects primarily children and young adults between the ages of ten and 25. Osteosarcoma often starts in the ends of bones, where new tissue forms as children grow. It occurs most often in the knee.
Chondrosarcomas, one of the most common types of bone cancer in adults over age 50, form in cartilage -- usually around the pelvis, knee, shoulder, or upper part of the thigh. These cancers make up 26 percent of all bone cancer cases.
Ewing's sarcoma usually occurs in the middle part of bones, arising most often in the hip, ribs, upper arm, and thighbone. Like osteosarcoma, this cancer affects primarily children and young adults between the ages of ten and 25. Ewing's sarcoma is responsible for 16 percent of bone cancer cases.
The following types of bone cancer are rare and occur primarily in adults:
- Fibrosarcomas usually appear in the knee or hip area. They can arise in older patients after radiation therapy for other cancers.
- Giant cell tumors, which usually begin in the knee, affect young adults most frequently, and women more often than men.
- Adamantinomas usually occur in the shinbone.
- Chordomas are found most often in the sacrum, which is the lower part of the spine, also known as the tailbone.
Metastatic Cancer to Bone
Metastatic bone cancer -- cancer that starts somewhere else in the body and then spreads to the bone -- is much more common than primary bone cancer. Although any type of cancer can spread to the bone, the most common types are those of the breast, lung, kidney, thyroid, and prostate. Bone metastases most often arise in the hip, femur (thighbone), shoulder, and spine. Like other types of cancer, those that start in the bone can also spread to other parts of the body.
