Prostate cancer (PCa) patients with bone metastases who receive early treatment with zoledronic acid (ZA) may have a lower six-month risk of death compared with patients not treated with bisphosphonates, data show.
Nancy Velde, MD, of the Southeast Louisiana Veterans Health Care System in New Orleans, and her colleagues studied 585 Veterans Affairs patients with PCa and bone metastases who had no documented skeletal-related events (SREs). The six-month mortality rate was 4.3% among those treated with ZA compared with 13.8% for men not treated with bisphosphonates, according to a report in Prostate Cancer and Prostatic Disease (2011;14:79-84).
Patients who received early ZA treatment were matched one-to-one by propensity score to patients not treated with bisphosphonates. The investigators defined early ZA treatment as having a ZA infusion after the first bone diagnosis date and before any recorded SREs. The final study sample included 73 pairs and there were no significant differences observed between the two groups in terms of baseline demographics, comorbidity profiles, or cancer treatment history.
The six-month SRE-free survival was 91.7% for the ZA group versus 71.5% for those without bisphosphonate therapy. The ZA group also had better hospitalization-free survival (80.5% vs. 66.3%).
In a previous study, ZA treatment was not associated with improved overall survival in bone-metastatic PCa patients, but the researchers noted that a large proportion of patients in that study had experienced skeletal complications before randomization.
ZA therapy has been shown to have anti-cancer activity in solid tumors and hematologic malignancies, and has been found to improve survival in early-stage breast cancer patients, a subgroup of lung cancer patients and patients newly diagnosed with multiple myeloma, according to the investigators.