[Bone hyperresorption in multiple myeloma]

OSTEOLYSIS AND HYPERCALCEMIA: Multiple myeloma is a type B high-grade lymphoproliferative syndrome with bone tropism. Bone-related manifestations--osteolysis and hypercalcemia--are observed in 80 and 30% of cases respectively. Excessive bone resorption subsequent to destruction of the bone matrix by osteoclasts is associated with insufficient bone formation. This process plays a determining role in the development of osteolysis and hypercalcemia in multiple myeloma patients. MECHANISM OF BONE DESTRUCTION: The reality and intensity of bone destruction is clearly demonstrated by histomorphometric studies and more recently by biochemical methods using markers of bone resorption. The excessive bone resorption results from complex interactions between tumor plasma cells, bone cells, and stem cells and involves local factors and adhesion molecules. BISPHOSPHONATES: Bisphosphonates are powerful inhibitors of bone resorption. They constitute a substantial advance in the management of bone manifestation in patients with multiple myeloma. Bisphosphonates not only have a well-established curative effect in patients with tumor-induced hypercalcemia, but also inhibit disease progression in bone.