Myeloma bone disease is due to the overexpression of receptor activator for nuclear factor κ B ligand (RANKL) by bone marrow stroma. RANKL activates osteoclasts, which resorb bone. The resultant bone lesions are lytic (cause breakdown) in nature, and are best seen in plain radiographs, which may show "punched-out" resorptive lesions (including the "raindrop" appearance of the skull on radiography). The breakdown of bone also leads to the release of calcium ions into the blood, leading to hypercalcemia and its associated symptoms. Anemia
The anemia found in myeloma is usually normocytic and normochromic. It results from the replacement of normal bone marrow by infiltrating tumor cells and inhibition of normal red blood cell production (hematopoiesis) by cytokines. Impaired kidney function
Impaired kidney function may develop, either acutely or chronically, and with any degree of severity. The most common cause of kidney failure in multiple myeloma is due to proteins secreted by the malignant cells. Myeloma cells produce monoclonal proteins of varying types, most commonly immunoglobulins (antibodies) and free light chains, resulting in abnormally high levels of these proteins in the blood. Depending on the size of these proteins, they may be excreted through the kidneys. Kidneys can be damaged by the effects of proteins or light chains. Increased bone resorption leads to hypercalcemia and causes nephrocalcinosis, thereby contributing to kidney failure. Amyloidosis is a distant third in the causation.
With high-dose therapy followed by ASCT, the median survival has been estimated in 2003 to be about 4.5 years, compared to a median around 3.5 years with "standard" therapy.The international staging system can help to predict survival, with a median survival (in 2005) of 62 months for stage-1 disease, 45 months for stage-2 disease, and 29 months for stage-3 disease. The median age at diagnosis is 69 years. Genetic testing
SNP array karyotyping can detect copy number alterations of prognostic significance that may be missed by a targeted FISH panel. Epidemiology
Globally, multiple myeloma affected 488,000 people and resulted in 101,100 deaths in 2015. This is up from 49,000 in 1990. United States
In the United States in 2016, an estimated 30,330 new cases and 12,650 deaths were reported. These numbers are based on assumptions made using data from 2011, which estimated the number of people affected as 83,367 people, the number of new cases as 6.1 per 100,000 people per year, and the mortality as 3.4 per 100,000 people per year. Multiple myeloma is the second-most prevalent blood cancer (10%) after non-Hodgkins lymphoma. It represents about 1.8% of all new cancers and 2.1% of all cancer deaths.Multiple myeloma affects slightly more men than women. African Americans and native Pacific Islanders have the highest reported number of new cases of this disease in the United States and Asians the lowest. Results of one study found the number of new cases of myeloma to be 9.5 cases per 100,000 African Americans and 4.1 cases per 100,000 Caucasian Americans.