Bone formation markers and pain palliation in bone metastases treated with strontium-89.

In several bone disorders, including those with metastatic involvement, changes in procollagen type I C-terminal and type III N-terminal peptides are detected, as indications of altered bone metabolism. Assessment of bone turnover could play a role in the evaluation of response to Strontium-89 used as palliative treatment in symptomatic bone metastases from various primary tumors. A correlation between bone formation rate markers procollagen I and III and efficacy of ionic Strontium-89 was shown in a group of 13 patients who underwent treatment with 4 mCi of Strontium-89 for painful bone metastases: 5 from breast, 7 from prostate, and 1 from lung carcinoid cancer. Assessed as a modification of analgesic intake, pain, and ambulation, there were 6 complete remissions, 3 partial remissions, and 4 nonresponders. The duration of the response was from 2 to 11 months. Procollagen I and III levels were found to be highly abnormal in those with no benefit from Strontium-89 administration but were in the normal range or only slightly elevated in those achieving complete or partial pain control, thus correlating with the clinical response.