Bone cancers may be primary or secondary. a skeletal malignancy occurring primarily as a sarcoma in an area of rapid growth or, secondarily, as metastasis from cancer elsewhere in the body.

Primary bone tumors are rare. It occurs as a sarcoma in an area of rapid growth, usually the long bones. The incidence peaks during adolescence, decreases, and then rises slowly after the age of 35. In adults, bone cancer is linked to exposure to ionizing radiation. Paget's disease, hyperparathyroidism, chronic osteomyelitis, old bone infarcts, and fracture callosities increase the risk of many bone tumors.

Unlike primary bone tumors, secondary bone cancers are due to spread from a remote site. Most secondary bone cancers are found in the spine or pelvis and less often in sites away from the trunk. Secondary bone tumors are almost never seen in the long bones.

Bone cancers progress rapidly but are often difficult to detect. Bone pain that increases at night may be the only symptom.

X-ray films, radioisotopic scans, arteriography, and biopsies are diagnostic; alkaline phosphatase levels are elevated in osteoblastic cancers, and serum calcium and urinary calcium are increased in highly destructive bone lesions.

The most common osseous malignancies are osteosarcomas, followed by chondrosarcomas, fibrosarcomas, and Ewing's sarcoma.

Surgical treatment consists of local resection of slow-growing tumors or amputation, including the joint above the tumor, if the lesion is aggressive. Radiotherapy may be given preoperatively or as the primary form of treatment of radiosensitive tumors, such as Ewing's sarcoma and reticulum cell sarcoma.

DR SOON is a medical practitioner. He holds four degrees. MBBS (University of Malaya), MBA (University of East Asia), LLB (Hons) (University of Wolverhampton), Master of Medicine (Edith Cowan University)