Quantifiable Excess of Bone Resorption in Monoclonal Gammopathy Is an Early Symptom of Malignancy: A Prospective Study of 87 Bone Biopsies

To determine if excessive osteoclastic-mediated bone resorption (BR) is an early tumor-induced event in multiple myeloma (MM), BR was assessed at first presentation on quantitative bone biopsy in 87 individuals evaluated for monoclonal gammopathy of undetermined significance (MGUS) and reinterpreted according to the presenting features and subsequent follow-up evaluation. As a reference population, 48 patients with previously untreated overt MM were evaluated under similar conditions. The median level of BR was significantly higher in 48 overt MM versus 87 MGUS patients (12.2% v 5.1% [normal level, or