Usefulness of strontium-89 for bone pain palliation in metastatic breast cancer patients

Most studies of prostate cancer have shown that strontium-89 chloride (Sr-89) is effective in the palliation of metastatic bone pain, refractory to conventional analgesia. The aim of this study was to evaluate the usefulness of Sr-89 for bone pain palliation in breast cancer patients. Forty women were treated with 148 MBq of Sr-89. Six patients were retreated, receiving two or more doses. The Karnofsky performance status was assessed and pain and analgesia were scored on scales of 9 and 5 points, respectively. The efficacy of Sr-89 was evaluated at 3 months of treatment. The response was good in 60% of the patients and partial in 32%; there was no response in the remaining 8% (pre-treatment Karnofsky less than or equal to 60). The duration of the response was 120 +/- 143 days. In the patients retreated, the response was good in 83% and partial in 17%, without significant differences compared with the first dose, but the pre-treatment Karnofsky and the duration of the efficacy were lower (P<0.05). A transient and slight decrease of leukocyte and platelet counts after the first month of treatment with Sr-89 was observed. In conclusion, breast cancer patients with metastatic bone pain can benefit from therapy with Sr-89. If necessary, the treatment may be repeated safely and with the same efficacy as is achieved after the first dose. A low functional performance status could be a cause of the lower effectiveness of Sr-89. ((C) 2000 Lippincott Williams & Wilkins).