Myeloma—also called multiple myeloma because myeloma cells usually cluster in multiple sites of the body—is cancer of the plasma cells, a type of white blood cell. Plasma cells are an important part of the immune system because they produce antibodies called immunoglobulins that help people fight infection.
Myeloma begins in the bone marrow—the soft, spongy tissue that fills the center of bones. The bone marrow is where blood cells such as red blood cells, white blood cells, and platelets are made.
Patients with multiple myeloma develop an excessive number of abnormal plasma cells in their bone marrow. The cancerous plasma cells multiply, building up in the marrow and crowding out normal, healthy blood cells. This buildup of myeloma cells can lead to various medical problems and complications, like a reduction in blood cell production, damage to the surrounding bones, organ damage, and problems with blood clotting and circulation.
There is currently no cure for the majority of multiple myeloma patients. However, it is a treatable disease and many patients are able to live full-filling lives for 10 years or more after being diagnosed if treated with the best available therapies.
Symptoms of Myeloma
In the early stages of multiple myeloma, symptoms may be vague and resemble other conditions. Many cases of multiple myeloma are now discovered during a routine blood test, when protein levels are found to be elevated and myeloma is suspected.
As the disease progresses, some of the following symptoms can occur:
Tiny fractures in the bones resulting from an accumulation of plasma cells and bone-dissolving cells called osteoclasts are common in people with multiple myeloma. Bones may become weak and prone to breaking. Pain is often felt in the lower back, pelvis, ribs, and skull.
Spinal cord compression, which causes nerve damage, is one of the most severe effects of myeloma. About 70% of myeloma patients have disease-related bone lesions. Magnetic Resonance Imaging, or MRI, and PET/CT scans can determine whether or not bone tumors or lesions exist and where in the body they are located.
To manage skeletal symptoms, patients are usually asked to take calcium supplements and bone-strengthening medications, such as pamidronate (Aredia) or zoledronic acid (Zometa) and avoid straining the spine by not carrying heavy weight. Injections of a cement-like substance into the spine, known as vertebroplasty or kyphoplasty, may be needed to prevent further collapse of spine bodies.
As a result of increased bone destruction, excess calcium can build up in the blood, causing a condition called hypercalcemia. This condition calls for urgent treatment. Raised calcium levels can take a toll on the kidneys and cause fatigue, muscle weakness, loss of appetite, nausea, and confusion.
If left untreated, excess amounts of myeloma protein can cause kidney damage or even renal failure. A kidney biopsy might be performed to determine the exact cause of the kidney damage.
To manage kidney problems, patients should stay hydrated and avoid non-steroidal anti-inflammatory drugs and intravenous contrast agents.
In myeloma patients, it is common that the growth of red blood cells—which carry oxygen throughout the body—is inhibited. If the development of red blood cells is depressed, anemia can result. Anemia causes extreme tiredness, weakness, and dizziness. It can also cause shortness of breath. The vast majority of myeloma patients develop anemia.
To manage anemia, patients receive growth factors that stimulate the growth of red blood cells, such as Procrit or Aranesp, and may also need to receive blood transfusions.
Myeloma patients have reduced white blood cell counts, meaning their bodies are less likely to produce the lymphocytes and antibodies necessary to fight infection. Therefore, patients are at significant risk of contracting infections, like pneumonia, urinary tract infections, and shingles. Receiving chemotherapy can further reduce white blood cell counts, putting a patient at even greater risk.
Patients will often be given antibiotics to manage infections. If infections are recurrent and life-threatening, intravenous immunoglobulin therapy may be necessary.
Nervous system complications
Collapsing bone structures can impede on nerves, causing severe pain, numbness, tingling, and muscle weakness. Polyneuropathy, which occurs when peripheral nerves throughout the body malfunction simultaneously (typically starting in the feet), can be caused by amyloidosis, a rare complication of myeloma, and also by medications such as Thalidomide, Velcade, and Vincristine.
Thickening of the blood
The abnormal proteins produced by myeloma cells can cause a dangerous thickening of the blood, also known as hyperviscosity. When blood is resistant to flowing properly and becomes thick and sticky, the result can be bruising, nose bleeding, gastrointestinal bleeding, hazy vision, confusion, numbness in the extremities, chest pain, and shortness of breath. Plasmapheresis, a procedure by which the thick blood is replaced by other fluids, may be needed in such cases.