Mechanisms of Bone Metastasis

Abstract

One metastases are a frequent complication of cancer, occur- ring in up to 70 percent of patients with advanced breast or prostate cancer 1 and in approximately 15 to 30 percent of patients with carcinoma of the lung, colon, stomach, bladder, uterus, rectum, thyroid, or kidney. The exact incidence of bone metastasis is unknown, but it is estimated that 350,000 people die with bone metastases annually in the United States. 2 Furthermore, once tumors metastasize to bone, they are usually incurable: only 20 percent of patients with breast cancer are still alive five years after the discovery of bone metastasis. 3 The consequences of bone metastasis are often devastating. Osteolytic metastases can cause severe pain, pathologic fractures, life- threatening hypercalcemia, spinal cord compression, and other nerve-compression syn- dromes. Patients with osteoblastic metastases have bone pain and pathologic fractures because of the poor quality of bone produced by the osteoblasts. For all these reasons, bone metastasis is a serious and costly complication of cancer.