by Dr JV Sangkar
Multiple myeloma (also known as myeloma or plasma cell myeloma) is a haematologic disorder, meaning it develops in the blood.
It is a disorder of the plasma cell, an important part of the immune system that produces immunoglobulins (antibodies) that help fight infection and disease.
There are many types of blood cells in circulation and the three most important are red blood cells (which carry oxygen to all the body’s cells), white blood cells (which are essential for fighting infection) and platelets (which help the blood to clot to prevent bleeding).
One type of white blood cell is lymphocytes, from which plasma cells develop.
Plasma cells produce proteins called immunoglobulins (Ig), also known as antibodies, that help fight disease and infection.
Abnormal Protein Secretion
Myeloma is generally a disease involving plasma cells, leading to abnormal protein secretion called monoclonal (M) protein or paraprotein, in large quantities.
Unlike normal immunoglobulin, M protein does not benefit the body. Instead, it crowds out normal, functional immunoglobulins. In addition, levels of functional immunoglobulin are depressed in individuals with myeloma.
The term myeloma comes from the word 'oma' or tumour, involving the blood producing cells in the bone marrow or 'myelo'. A malignant or cancerous plasma cell is known as a myeloma cell.
Myeloma is called 'multiple' since the usual clinical presentation is multiple areas on the bones where tumours or lesions have developed (as seen on x-ray or MRI imaging). In comparison a single lesion is termed solitary plasmacytoma.
Since plasma cells normally reside in the bone marrow, the disease starts in the areas where the marrow is active, such as within the bones of the spine, skull, pelvic bones, rib cage and areas around the shoulder and hips.
Unlike other bone cancers, areas around the hands, feet and lower arm/leg are usually spared.
Causes and Symptoms
Although it is generally reported and published that myeloma is a disease of the elderly population (average age at diagnosis is 68 years), we now see many younger patients with more aggressive disease.
There is no definite report of the incidence of multiple myeloma in Malaysia, but it is relatively a common disease referred to the practising haematologist. The male:female ratio is approximately 1:1.
There has been no clear report on the likely causes of this disease, although exposure to radiation has a higher incidence. Myeloma, like other cancers, is not infectious and cannot be passed on to other people.
The main symptom of myeloma is often back pain as it commonly affects the bones of the spine.
Other bones may also be affected, such as the ribs, neck or pelvis. Other common symptoms may include any of the following : anaemia (lethargy, weakness, palpitation, shortness of breath), bone pain, bone fracture from simple injury and unresolved infections.
Frequently the patient is referred from another doctor for an incidental detection of an abnormal blood result.
Laboratory tests and medical procedures are used to confirm a diagnosis of myeloma. These tests are conducted on all patients as part of an initial evaluation. The results will help in determining the disease level at diagnosis and deciding on treatment options.
It also provides a baseline against which disease progression and response to therapy can be measured.
Myeloma is rarely curable, but it is treatable, and treatment can be very effective at controlling symptoms and stopping the development of the disease.
To determine the prognosis (forecast or likely outcome of a disease) of multiple myeloma, the extent or the stage of the disease is assessed, based on the existence of different signs, symptoms, and circumstances.
Some people with myeloma who have no symptoms may not initially need any treatment, however treatment will be started if the myeloma begins to progress or if symptoms occur.
Glucocorticoids (steroids) appear to be an anchor drug when treatment is recommended. Various combinations of chemotherapy agents have been used with fairly similar results.
Thalidomide and its derivatives have made a flashing comeback into clinical practice and have produced promising results in treating myeloma.
Bisphosphonates are used to reduce and prevent myeloma-related bone damage, and to reduce the risk of skeletal-related events like spontaneous fracture.
Newer drugs like proteosome inhibitors have revolutionised myeloma treatment by showing remarkable benefits and have been made a platform for comparison amongst the available treatments.
The role of stem cell transplantation, particularly autologous peripheral blood stem cells (a procedure in which stem cells are removed from a patient’s blood and then are given back to the patient following intensive treatment), in a medically fit patient has been a target end-point in the pathway for myeloma management, especially as a definite consolidating therapy for sustaining long-term complete remission status.
More info on MULTIPLE MYELOMA here.