INTRODUCTION

Multiple myeloma (MM) is hampered by a number of complications that can result in a poor quality of life and in many instances are contributory causes of death. In this chapter, the treatment of the most frequent complications such as bone disease, renal function impairment, anemia, infections, nervous system involvement, and extramedullary disease are reviewed.

SKELETAL COMPLICATIONS

Incidence and pathogenesis

Bone involvement is the most frequent clinical complication in patients with MM. In this sense, approximately 70% of patients have lytic bone lesions with or without osteoporosis and other 20% have severe osteoporosis without lytic lesions. The skeletal involvement leads to bone pain and can result in pathological fractures. Bone disease in MM results from an imbalance between increased resorption and decreased bone formation. Thus, both malignant plasma cells and bone marrow stromal cells can produce osteoclast-stimulating cytokines such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α; (TNF-α). Moreover, the interaction between the receptor activator of nuclear factor-κB (NF-κB) (RANK) and RANK ligand can play an important role in cancer-associated bone disease. It seems that the bone involvement in MM is the consequence of an alteration in the cytokine production by the bone marrow microenvironment, thus resulting in the uniform pattern of skeletal involvement. Thus, it has been observed by these authors that patients without lytic lesions at the time of diagnosis usually do not develop lytic lesions later in the course of the disease. These patients commonly have or develop progressive osteopenia resulting in rib or vertebral fractures.