Radiotherapy can take the form of external-beam or radioisotope radiation. With localized irradiation, most patients who have painful lesions experience at least partial relief, often within a few weeks.12,37 It may be used postoperatively, as well, to decrease the chances of disease progession.20
Systemic therapies include chemo- and hormone therapies. Chemotherapy effectiveness is highly dependent on the primary tumor type. For example, renal cell carcinoma and melanoma are often resistant, while lymphoma and germ-cell tumors may be eliminated and sometimes even cured.7 Hormone therapy can be highly effective in selective cancers, primarily breast and prostate cancers. Immunotherapy options may also be used to specifically target bone metastasis sites.
Bone-modifying agents include bisphosphonates and denosumab (Prolia, Xgeva). These are generally initiated at the discretion of the oncologist, but primary care physicians should be familiar with their use. Bisphosphonates, which includes zoledronic acid, pamidronate, and other agents, are analogues of pyrophosphate that inhibit bone demineralization.38 These agents target bone resorption through incorporation into osteoclasts and have been effective in the treatment of hypercalcemia and bone lesions.6,12,39 Not only do they reduce the incidence of all skeleton-related events, including pathologic fractures and pain, they also appear to have antitumor activity with prolonged survival in certain cancers.7,12
Denosumab, which has a much shorter half-life than bisphosphonates, is a monoclonal antibody that targets the gene RANKL, a key activator of osteoclasts, and thereby prevents the development of osteoclasts and related bone resorption.40
Radiofrequency ablation or cryoablation, using image-guided needle placement, specifically targets individual bone lesions, destroying tumor cells with extreme heat or cold, respectively. This has been shown to reduce pain and opioid consumption.41
Continue to: Managing pain