ABSTRACT
Bone represents the most common site of metastases for many solid tumors.
Metastases to bone develop in nearly 70% of patients with either breast or prostate
cancer, and in approximately 15% to 30% of patients with other solid tumors
(lung, colon, thyroid, renal cell, bladder, uterine, or rectal) (1,2). Significant
complications result from bone metastasis including hypercalcemia, pathologic
fractures, spinal cord compression, and severe bone pain, representing a signifi-
cant source of morbidity and mortality for patients (2,3). While any form of cancer
metastases is associated with a shortened survival, those with metastases to bones
only (particularly with breast and prostate cancer) live, on average, years longer
than those with visceral metastasis (1,4). Median survival of patients with cancer
metastases to bone is on an average 19 to 25 months (5). A mainstay of treatment
for bone metastases for the past several years has consisted of bisphosphonate
therapy; however, recent advances have identified newer targets and agents, many
of which are currently in clinical trial development.
