Clinical experience with strontium-89 in prostatic and breast cancer patients

Bone metastases are a major problem in the clinical management of patients with breast or prostate cancer. Severe bone pain can be a particularly debilitating effect of metastatic disease, resulting in a growing dependency on opioid analgesics and a reduced quality of life in patients who have a short time to survive. The radiopharmaceutical strontium-89 has been demonstrated to be generally well tolerated as well as effective in reducing metastatic bone pain in breast or prostate cancer patients. Unlike other radioisotopes or external radiation treatments, it represents systemic, targeted therapy that is simple and fast to administer in an outpatient setting. Data accumulated over the last 15 years demonstrates that 89Sr provides pain relief in up to 80% of patients with bony metastases arising from breast or prostatic malignancies. Pain palliation is maintained for several months, along with improvements in functional status and quality of life. As many as one fifth of 89Sr-treated patients become pain free and require no further pain medication. The adverse effects of intravenous 89Sr are minimal. Bone marrow toxicity is observed in many patients, resulting in some reduction of platelet and white blood cell counts. Despite reductions of 20% to 30%, these hematologic effects are generally reversible and the majority of patients maintain platelet counts that are within normal limits. Strontium-89 is effective systemic radioisotopic therapy for the palliation of painful bony metastases from breast and prostate carcinoma.