Multiple myeloma is a cancer of plasma cells, the cells that produce antibodies. All blood cells develop in the bone marrow from stem cells. Certain built in ‘growth factors’ cause the stem cells to differentiate into many types of blood cells. Plasma cells develop from B lymphocyte cells. If a stem cell that is destined to become a B cell is damaged, it may become malignant (cancerous). The malignant cells then spread through the bone marrow to all the large bones of the body. Patients with myeloma often develop soft spots where the bone structure is damaged. The malignant plasma cells force out the normal cells and produce a substance that causes bone destruction.
Many patients with multiple myeloma show no symptoms for a long time. However, most patients eventually develop some evidence of the disease such as lower back or rib pain, anaemia and fatigue. Diagnosis may be made when a routine FBC is abnormal, showing anaemia, an abnormal clumping of red blood cells (‘Rouleaux’), and white blood cell irregularities. Further testing is usually necessary to pinpoint the cause of the abnormal results. These tests may indicate an increase in serum or urine proteins, with abnormal patterns on protein electrophoresis and immunofixation. In some patients, increased blood urea and creatinine due to decreased kidney function and high serum calcium (hypercalcaemia) due to bone destruction may occur. Examination of a bone marrow biopsy may be needed for a definitive diagnosis. Other diagnostic tests may include x-ray, MRI and CT scan to show the soft spots in bones.
Current treatments may produce a complete remission (disappearance but not cure of the disease). These may include the use of bisphosphonates, chemotherapy, stem cell transplant and thalidomide. Other treatments include radiation therapies and immunotherapy, which stimulates the body’s own system to produce an immune response. Your doctor should determine your treatment based on the findings of your tests.