Novel therapeutic approaches to cancer patients with bone metastasis.

Bone metastases are a common event in advanced cancer. Breast, lung, prostate and thyroid neoplasms have striking osteotropism. Bone metastatic cancer may be associated with catastrophic consequences for the patients. Therefore, new strategies are warranted in order to reduce the incidence of bone metastases and to palliative established skeletal disease. External beam radiation therapy, endocrine treatments, chemotherapy, bisphosphonates and radioisotopes are all important. Bisphosphonates have become the treatment of choice for tumor-induced hypercalcaemia and more recently they have been used alone or in combination with cytotoxic agents in the palliative treatment of patients with bone metastases. The results are encouraging. Currently, new bisphosphonates that are a hundred times more powerful with respect to clodronate and pamidronate are under investigation. The treatment of metastases to bone and mechanisms of pain relief after radiation therapy are poorly understood. Up to date, there are not standard criteria for the irradiation of bone metastases and bone pain relief may be reached using a variety of fractionation schemes. Radionuclide therapy is the systemic use of radioisotopes for bone pain. It is currently regarded as suitable for comparison with wide-field irradiation, but appears to have major disadvantages in terms of pain relief and toxicity.