The likelihood of prostate cancer cells metastasizing to bone has an early and important influence on the natural history of prostate cancer. Bone-targeted therapy, when given sequentially with hormonal therapy (androgen suppression) and radiation therapy, prolongs the progression of the disease in clinically non-metastatic prostate cancer patients.
The use of Samarium-153 EDTMP in conjunction with hormonal therapy and external beam radiation therapy has never been previously evaluated in high risk clinically localized prostate cancer. Many patients with high-risk prostate cancer develop progressive disease within 2 years of therapy indicating that subclinical metastatic disease may be present at the time of initial diagnosis. In these high-risk patients, there may be a therapeutic benefit of combining hormonal therapy with external beam radiation therapy and Samarium-153 EDTMP to treat localized and subclinical bony disease, respectively.