Multiple myeloma is a cancer of plasma cells. These plasma cells are part of white blood cells formed from B lymphocytes. The function of plasma cells is to generate immunoglobulins and when these cells become abnormal, there is overproduction of these monoclonal immunoglobulins and light chains. Plasma cells can take up to 10% of the cell space in bone marrow, which comprises only 2-3% normally. Therefore, this overproduction of plasma cells is inversely proportional to the number of other blood cells found in the bone marrow, which include red blood cells, white blood cells and platelets. Therefore, most of the clinical sequelae are due to deficiency of these blood cells, skeletal pathology due to bone marrow involvement and deposition of these abnormal immunoglobulins in different body tissues and organs.
Is Multiple Myeloma A Fatal Disease?
Although the advances in treatment have increased the survival rate of patients with multiple myeloma, the condition is still fatal. The patients still die, though a few years later. It is the second most common blood cancer and is increasing in incidence. Although, the death rate has reduced to a considerable amount, the prognosis is still poor for the elderly patients, who are most commonly afflicted by the condition. The 5 year survival rate of multiple myeloma patients is 46.6% and the survival rate ranges from 1-10 years depending on the severity and progression of the condition. There is no definitive cure for the condition, but advances in treatment have managed to increase the life span of the patients. Hopefully, in future the disease will be just a chronic disease than a fatal disease. (1)
Although, the exact cause of multiple myeloma is still unknown, there have been various theories regarding the etiology of the disease. It has been attributed to genetics, as it is more common in twins and first degree relatives of the patient. It has also been attributed to environmental factors and occupational exposure to herbicides and insecticides (such as chlordane), long term exposure to hair dyes, benzene and other organic solvents. MGUS (monoclonal gammopathy of undetermined significance) or SMM (smoldering multiple myeloma) have been implicated in progression to multiple myeloma. Radiation is also considered a risk factor for multiple myeloma as the people exposed to Nagasaki atomic bomb were found to have increased cases of multiple myeloma. Infections and chronic inflammation have also been implicated in the etiology of multiple myeloma.
Signs And Symptoms Of Multiple Myeloma
Multiple myeloma presents with varied signs and symptoms and sometimes it may be diagnosed after a laboratory test in relation to other problems. The common presenting signs of multiple myeloma are pathological fracture, anemia, leucopenia, thrombocytopenia, hypercalcemia, hyperviscosity, spinal cord compression, renal failure and amyloid deposition. The symptoms related to these conditions include fatigue, weakness, pale skin, dehydration, bone pain, infections, easy bruising and bleeding, purpura, paresthesias, dysesthesias of the lower extremity, sensory loss, paralysis, nausea, fever, malaise, muscle cramps, polydipsia, polyuria, constipation, diarrhea, somnolence, altered mental state, kidney stones, headaches, seizures, hazy vision, papilledema, neuropathy, myopathy, carpal tunnel syndrome, soft tissue masses, macroglossia, skin lesions, bilateral swelling of shoulder joints, distension of abdomen due to hepatomegaly and splenomegaly. Renal failure may occur due to abnormal immunoglobulin deposition in the kidneys. These depositions in the heart may lead to cardiomegaly, ischemia, infarction and stroke when deposited in the brain.
Diagnosis And Treatment Of Multiple Myeloma
The diagnosis of multiple myeloma involves the clinical evaluation of eyes, skin, neurological, abdomen, cardiovascular system and musculoskeletal system along with routine blood tests. Other tests to be carried out include serum and urine testing for monoclonal proteins, serum free light chain assay, serum testing for immunoglobulins, beta-2 microglobulin, albumin, lactate dehydrogenase, FISH, skeletal survey, MRI, cytogenetics, bone marrow aspiration or biopsy.
The treatment involves chemotherapy and immunosuppression, radiation therapy, surgery in selected cases, and autologous stem cell transplantation. The treatment also involves the management of associated complications. The chemotherapeutic drugs used are steroids, thalidomide, lenalidomide, bortezomib, melphalan, vincristine, doxorubicin, cyclophosphamide, carfilzomib, ixazomib, cisplastin, etoposide and elotuzumab. These drugs are used in various combinations.