Prognostic value of serum markers of bone metabolism in untreated multiplemyeloma patients

Bone involvement is a central feature of multiple myeloma (MM). We investig ated whether serum markers of osteoblastic and osteoclastic activity correl ate with the presence of bone disease and survival in 313 MM patients enrol led in a phase III trial (E9486). Five markers were measured, including ost eocalcin (OC), carboxy-terminal propeptide of type I collagen (PICP), bone alkaline phosphatase (BAP), carboxy-terminal telopeptide of type I collagen (ICTP) and tartrate-resistant acid phosphatase (TRAP). We analysed the rel ationship between serum levels of these markers and the presence of bone ma nifestations, and survival. Serum levels of ICTP and BAP correlated signifi cantly with bone pain, lesions and fractures. Serum level of ICTP was also higher in stage II-III compared with stage I disease. The serum level of IC TP was significantly associated with shortened survival in the univariate a nalysis. The median survival times were 4.1 and 3.5 years for low and high ICTP respectively (P = 0.02). There was a strong relationship between ICTP and beta-2-microgolobulin (B2M). ICTP stands out as a significant marker of bone disease. Incorporation of these markers into clinical trials assessin g the use of bisphosphonates in MM is needed to determine whether they migh t serve as indicators of effectiveness of these agents.