Abstract: Improved understanding as to the biology of multiple myeloma (MM) and the bone marrow microenvironment has led to the development of new drugs to treat MM. This explosion of new and highly effective drugs has led to dramatic advances in the management of MM and underscores the need for supportive care. Impressive and deep response rates to chemotherapy, monoclonal antibodies, and small molecule drugs provide hope of a cure or prolonged remission for the majority of individuals. For most patients, long-term, continuous therapy is often required to suppress the malignant plasma cell clone, thus requiring clinicians to become more astute in assessment, monitoring, and intervention of side effects as well as monitoring response to therapy. Appropriate diagnosis and monitoring strategies are essential to ensure that patients receive the appropriate chemotherapy and supportive therapy at relapse, and that side effects are appropriately managed to allow for continued therapy and adherence to the regimen. Multiple drugs with complex regimens are currently available with varying side effect profiles. Knowledge of the drugs used to treat MM and the common adverse events will allow for preventative strategies to mitigate adverse events and prompt intervention. The purpose of this paper is to review updates in the diagnosis and management of MM, and to provide strategies for assessment and monitoring of patients receiving chemotherapy for MM.
Keywords: multiple myeloma, treatment, symptoms, assessment, monitoring, symptom management, targeted therapies
Multiple myeloma (MM) is an incurable, but highly treatable cancer characterized by an overproliferation of bone marrow plasma cells, which leads to the production of a monoclonal protein. Through a series of genetic changes, genetic mutations, and cellular alterations, the normal plasma cell turns malignant. Cancerous plasma cells overproduce clonal immunoglobulin (Ig) proteins which cause organ destruction. Although the genetic makeup of the tumor itself and patient symptoms at presentation are heterogeneous, common signs and symptoms of MM exist at diagnosis. Known as “CRAB” criteria, the pneumonic stands for hyperCalcemia, Renal insufficiency, Anemia, and Bone damage. The incidence of these at diagnosis is as follows: anemia 73%, bone pain 68%, renal insufficiency 19%, and hypercalcemia 13%.1 To delay worsening of existing organ damage, or to prevent future organ damage, prompt treatment of the malignant plasma cells with chemotherapy is warranted.
As of 2012, it is estimated that 65,000 individuals are living with MM globally and comprise ~2% of all cancer types.2 The incidence of MM is expected to increase over the next decade. The etiology of MM is unknown, but the risk is associated with increasing age, obesity, and race. MM is more prevalent in individuals over the age of 65 and is nearly two times higher in African–American individuals and men. Obesity and high body mass index further increases the risk to develop monoclonal gammopathy of undetermined significance (MGUS) and potential MM.3