Multiple Myeloma Cancer
Multiple myeloma cancer also referred to as plasma cell myeloma, is a plasma cells malignancy involving antibody producing cells-B lymphocytes. The disorder is characterized by accumulation of abnormal plasma cells in the bone marrow and production of M-protein (an abnormal form of antibody). Accumulation of the abnormal cells cause impaired functioning of the bone marrow resulting to abnormal production of other blood cells. The M-protein is associated with kidney problem and bone lesion, while other complications such as hypercalcemia are also associated with multiple myeloma. Chromosomal aberrations result to the lost control of lymphocyte proliferation and antibody production by the immune system resulting to overproduction and accumulation of the cells and osteoporosis. The disorder accounts for approximately 10% of hematologic cancers and the asymptomatic (monoclonal gammopathy of undetermined significance) is estimated to be present in 3% of the population above 50 years and progresses to myeloma at 1% per year (Kyle & Rajkumar, 2008). Multiple myeloma cancer is diagnosed through examination of plasma cells from bone marrow aspirate, antibodies from blood serum and examination of organ damage such as bone lesion and renal failure (Kyle & Rajkumar, 2004). Progression is in three stages and survival time is estimated to be 3-4 years but can range from 6 months to over 10years (Greipp et al., 2005). The disorder is treatable but not curable since it results from chromosomal changes that are irreversible. Drugs, radiotherapy and stem cell transplant are some of the treatments, some of which are quite costly especially stem cell transplant.
Development of multiple myeloma starts with evolution of monoclonal gammopathy of undetermined significance (MGUS) and latter progression of myeloma. In MGUS, there are limited clonal plasma cells and patient exhibit no symptoms and show no organ damage, although they may be at risk of progression to myeloma at a rate of 1% per annum. This pathogenetic step involves translocation on chromosome 14q32 at immunoglobulin heavy chain locus and either of the chromosomes; 4p16.3, 20q11, 11q13, 6p21 and 16q23. Progression to myeloma involves various genetic occurrences in neoplastic plasma cell, changes in microenvironment of the bone marrow, suppression of cell-mediated immune response, development of paracrine signaling loops involving IL-6 and induction of angiogenesis.
Figure 1: MCUS progression to myeloma (Kyle & Rajkumar, 2004).
According to Kyle & Rajkumar (2004), tumor persistence and its drug resistance results from the interaction of myeloma cells, microvessels and bone marrow stromal cells. Moreover, bone lesions are associated with increased expression of osteoblasts of receptor that activates factor-kB ligand and reduced levels of osteprotegerin. Multiple myeloma cancer has various risk factors such as race, old age, family history, gender, obesity, radiation exposure and other plasma cell disorders such as plasmocytoma (Dugdale & Chen, 2012). Prevention of the cancer therefore revolves around the avoidance of frequent radiations and control of body weight to reduce the risks. However, chromosomal alterations may pose a great challenge in prevention of the cancer thus treatment becomes crucial in case of the disorder development. Transplantation with own stem cells after a chemotherapy with bortezomib, lenalidomide and thalidomide becomes initial treatment, while the therapy is maintained with administration same drug. Relapse is however treated with initial therapy but with addition of other drugs such as cyclophosphamide and melphalan. Cancer treatment is a big burden to the world since over 10 million individuals live with cancer in the United States alone and the cost of treatment estimated at $72.1 billion in 2004 (Cook, 2008). According to Cook, although multiple myeloma cancer represents just 1% of all cancers, the cost is one of the highest. He further notes that approximately 19,920 individuals were to be diagnosed with multiple myeloma out of the estimated 1,437,1180 new cases projected in 2008. Men are at a higher risk than women and African American more than whites. Old age is another risk factor associated with development of multiple myeloma and the survival time is estimated to be 3-4 years although it depends on an individual’s exposure to aggravating factors such as obesity and radiation.
Multiple myeloma cancer is categorized into stages I, II and III and the system is referred to as international staging system (ISS). The staging is based on diagnostic criteria of the various stages in progression of multiple myeloma namely, asymptomatic, symptomatic and MGUS clinical test results of serum paraprotein, clonal plasma cells and end organ damage plus survival time of the patient as indicated in the table 1 below (Greipp et al., 2005).
|Stage||Criteria||Median survival (months)|
|I||Serum β2-microglobulin> 3.5mg/L||62|
|Serum albumin ≥ 3.5g/dL|
|II||serum β2-microglobulin < 3.5 mg/L but serum albumin < 3.5 g/dL or||44|
|serum β2-microglobulin 3.5 to < 5.5 mg/L irrespective of the serum albumin level|
|III||Serum β2-microglobulin ≥ 5.5mg/L||29|
Table 1: International staging system (Greipp et al., 2005)
Key: Stage II has two categories
In conclusion, multiple myeloma is a complicated cancer that is costly to treat and incurable. The fact that the alteration in the plasma cells interfere with the proliferation process of other blood cells makes it worse and dangerous. Treatment with chemotherapy is cheap but since the immune system is already compromised, it becomes necessary to use stem cell transplant, which is not affordable to many. Its association with obesity and radiation complicates the matter especially due to increased sedentary live by most in the developed and developing world and the increased use of radiation technology in treatment of various disorders.