The ZOTECT study: Effect of zoledronic acid on bone metabolism in patients with bone metastases from prostate or breast cancer

AbstractPurposeThe ZOTECT study assesses the effect of zoledronic acid (ZOL) on bone-marker levels and potential correlations with disease outcomes in bisphosphonate-naive patients.MethodsThis prospective, single-arm, open-label study in bisphosphonate-naive (≥6 months) patients with bone metastases from prostate cancer (PC; n=301) or breast cancer (BC; n=99) enrolled at 98 German sites (May 2006 to July 2008) investigated the effect of ZOL (4mg intravenously every 4weeks×4months, with a final follow-up at 12 months) on bone-marker levels. Secondary assessments: skeletal-related event (SRE) rate, pain, quality of life (QoL), and prostate-specific antigen levels. Endpoints were assessed using summary statistics by visit/tumor type and Kaplan–Meier analyses.ResultsZOL treatment significantly decreased bone-marker levels (amino-terminal propeptide of type I collagen [P1NP], C-terminal cross-linking telopeptide of type I collagen [CTX]; P<0.0001), and this decrease was maintained through the final 1-year follow-up visit. Baseline P1NP and CTX levels correlated with extent of bone disease (P