Association between bone turnover markers and skeletal-related events in patients with breast cancer and bone metastases on treatment with bisphosphonates: ZOMAR study results at nine months of follow-up.

594 Background: The presence of bone metastases (BMe) alters the balance of bone remodeling and, consequently, levels of bone turnover markers (BTM). Increased levels of these biomarkers are related to the risk of skeletal-related events (SREs), disease progression and death. Treatment with bisphosphonates reduces the number of SREs through osteoclastic activity inhibition. The aim of this study was to determine the correlation between BTM, bone metastasis development and SREs in patients (pts) with breast cancer (BC) and BMe. Methods: Observational, prospective, multicenter study. Inclusion criteria: pts with BC and BMe; no previous treatment that could interfere with bone metabolism in the last 6 months (mo) prior to inclusion. Urinary aminoterminal telopeptide of collagen I (NTX, Osteomark NTx Urine, Wampole Laboratories, USA), urinary alpha-alpha-isomer of carboxyterminal telopeptide of collagen I (αα-CTX, ALPHA Crosslaps EIA, ids, UK) and serum bone alkaline phosphatase (BALP, OSTASE BAP, ids, UK) we...