Most Skeletal-Related Events Due to Bony Metastases
SAN FRANCISCO—Skeletal-related events (SREs) in patients with metastatic hormone-refractory prostate cancer (mHRPC) are mostly due to bony metastatic disease and not decreased bone mineral density (BMD), according to British researchers.
A study by Nicholas D. James, MD, PhD, of The University of Birmingham, UK, and colleagues enrolled 86 men with mHRPC. Among the 86 patients in the trial, 12 (14%), 15 (17%), 2 (2%), and 3 (3%) had one, two, three, and four SREs related to metastatic disease, respectively.
The researchers defined SREs as symptomatic pathologic bone fracture, hypercalcemia, radiation therapy to bone, change to antineoplastic therapy to treat bone pain due to prostate cancer, cancer-related surgery to bone, or spinal cord or nerve root compression.
Seventy-eight patients underwent both dual energy x-ray absorptiometry (DXA) and a radionuclide bone scan at entry into the trial. Of these men, 49 (63%) had at least one site free of metastatic disease. At the lumbar spine, 22 patients (28%) had at least two analyzable vertebrae, whereas at the femoral neck, 45 (58%) had at least one analyzable hip. The investigators detected osteoporosis in three of the 49 patients. No SREs arising from decreased BMD occurred.
In a poster presented here at the Genitourinary Cancers Symposium, Dr. James' group concluded that SREs in men with mHRPC “are overwhelmingly due to bony metastatic disease, not diminished BMD.”
As most patients in the study did not experience SREs, the authors surmised that the active treatment of mHRPC prevents SREs that would otherwise result from disease progression.
“Strategies to prevent SREs in mHRPC patients should focus on the control of bony metastatic disease rather than preservation of BMD,” the researchers stated.
The symposium is sponsored by the American Society of Clinical Oncology, the American Society for Radiation Oncology, and the Society of Urologic Oncology.