In vivo models of prostate cancer metastasis to bone

Purpose: The metastasis of prostate cancer to bone is the most significant cause of morbidity and mortality in this disease. An estimated 28,900 men die annually secondary to prostate cancer bone metastasis. Current treatments increase survival for 2 months and only bisphosphonates offer any palliative benefit. This shortcoming is due in part to inadequate models in which to study the molecular biology of the disease and evaluate therapeutic regimens. We examined the breadth of models available that recapitulate the process of prostate cancer metastasis to bone. Materials and Methods: A PubMed search was done for publications concerning prostate cancer metastasis to bone and the imaging of bone metastases. Only studies focusing on model systems of disease progression and imaging of the process were included. Additional studies were found by cross-reference searching. Results: Prostate cancer metastasis to bone is a lengthy, complex process characterized by multiple stages. This has made it difficult to find adequate laboratory models in which to recreate the disease process. Each available model has characteristics of particular phases of disease progression to bone. The most widely used models are transgenic mice, variations of SCID mice, and the traditional orthotopic and xenotransplantation models. Furthermore, investigators have started to adapt their models to incorporate imaging modalities for following the progression of prostate cancer to bone. Conclusions: The development of models of prostate cancer metastasis to bone is an evolving discipline. A deeper understanding of the metastatic process has served to improve current models and it will continue to do so in the future.