[Bone disease in multiple myeloma]

Osteolytic bone disease in multiple myeloma (MM) affects more than 80% of patients. Bone disease results in severe bone pain, pathologic fractures, and hypercalcemia. These complications have not only a negative impact on quality of life but also effect in overall survival. MM bone lesions arise from the altered bone remodeling due to both increased osteoclast activation and decreased osteoblast differentiation. Myeloma cells directly stimulate the osteoclast formation, and induce various cells in the marrow microenvironment to produce factors that stimulate osteoclast formation and suppress osteoblast formation. Furthermore many factors produced by marrow stromal cells and osteoclast promote tumor growth through direct action on myeloma cells. Therefore, novel agents targeting bone disease are also promising therapeutic strategies for the treatment of MM.