Treatment with zoledronic acid (Zometa) before onset of skeletal morbidity may lower the risk of skeletal-related events (SRE) and prolong the time to the first SRE in men with bone metastases from prostate cancer, according to German researchers.
Manfred P. Wirth, MD, of University Hospital in Dresden, and his colleagues studied 284 such patients who received zoledronic acid 4 mg every four weeks for 15 months. Of the 284 men, 248 had no prior history of SRE. These patients had a 59% reduced risk of SREs compared with the 36 men who had a prior history of SRE.
During the study, the mean time to a first SRE for the whole group was 11.5 months, but it was significantly longer for the men who did not have a prior history of SRE (11.6 vs. 8.3 months). In addition, patients who had a prior history of SRE had a 2.4 times higher of experiencing another SRE.
In a separate study, investigators at Kings College Hospital in London showed that zoledronic acid decreases urinary levels of a bone marker (cross-linked N-telopeptides of type 1 collagen [NTx]) in patients with hormone-refractory metastatic prostate cancer.
At baseline and every three months, the researchers measured urinary NTx in 25 patients receiving zoledronic acid. The median follow-up was 12 months. The researchers observed no significant renal impairment. They concluded that zoledronic acid caused sustained and significant reductions in urinary NTx levels, indicating decreased bone resorption. “This may provide a useful tool to monitor the effect of bisphosphonate therapy,” they stated.