There is no single set treatment for bone metastases. Treatment depends on type of cancer, extent of the spread of metastases, prior treatment and other factors. Only a physician who is very familiar with the person's medical details can know what the best treatment is. However, in general terms treatment of bone metastases can be palliative (relief of symptoms) or curative. For many people with advanced cancer there may be no known effective cure so treatment may largely be focused on prolonging life and relieving the symptoms of bone metastases (eg. pain relief). However in certain cases where there is a chance of cure the treatment may include chemotherapy, radiotherapy and possibly bone marrow / stem cell transplantation.
See Cancer Pain and Palliative Care in Guide to Internet Resources for Cancer.