Multiple myeloma

Multiple myeloma is a type of cancer that originates in the bone marrow, specifically in the plasma cells, a type of white blood cell specialized in the production of antibodies. It accounts for 10% of hematological cancers.

In multiple myeloma, cancer cells accumulate and crowd out healthy cells. In addition, the aberrant plasma cells, instead of producing useful antibodies, produce abnormal proteins (M protein) that can cause complications. The cells become cancerous due to the presence of alterations in their genetic material, but the causes of multiple myeloma are not entirely clear.

However, there are certain factors that may increase the risk of developing the condition:

• Advanced age and gender. The risk increases markedly with age, developing especially after the age of 65. It is also more common in men than in women.
• Ethnic origin. The incidence of the disease is higher in people of African origin.
• Family history of monoclonal gammopathy of uncertain significance. This is a relatively benign disease which, like multiple myeloma, is characterized by an increase in M protein.

The symptomatology of multiple myeloma results from the uncontrolled proliferation of a clone of plasma (antibody-producing) cells in the bone marrow. Although some patients may not present any symptoms, the most common are the following:

• Bone problems such as pain, most commonly in the back, hips and skull, weakness and even fractures.
• Low blood cell counts, especially red blood cells (anemia), leukopenia and/or thrombocytopenia.
• Increased levels of calcium in the blood which may manifest with excessive thirst (polydipsia), polyuria, kidney problems, constipation, loss of appetite and/or abdominal pain, among others.
• Nervous system involvement which may manifest as back pain, numbness, muscle weakness, confusion or dizziness.
• Kidney damage due to accumulation of M protein that may be associated with weakness, itching or swelling.
• Recurrent infections. The decrease in immune system cells (leukocytes) causes multiple myeloma patients to become ill more frequently, and respond less well to treatment.

For certain types of cancer, risk factors are known to explain most cases. For others, there are early detection techniques that allow treatment before they become invasive cancers. However, in multiple myeloma, few cases are related to preventable factors, making prevention very difficult.

Multiple myeloma starts as a monoclonal gammopathy of uncertain significance or a bone plasmacytoma, but it is not known, for the moment, how to prevent its progression to multiple myeloma.