Dear Dr. Roach: My 72-year-old husband was diagnosed with multiple myeloma recently, and we have been told that he will need chemo treatments. He also has anemia, which I think is probably normal. He had a back injury in early February and a kyphoplasty in May, with a bone biopsy done routinely. After tests, we now have the diagnosis of multiple myeloma. What can be expected from this diagnosis? I understand that he has elevated kappa light chains.
A: Multiple myeloma is a type of blood cancer coming from plasma cells, the cells that make antibodies. As in any cancer, the cells reproduce uncontrollably. Damage from the cancer can come from what cancer cells produce, or by the fact that they take up necessary space and nutrition from the organs they occupy. In the case of multiple myeloma, the myeloma cells usually secrete immunoglobulins (antibodies, or parts of antibodies). Kappa chains are a component of antibodies (so are lambda chains, the other type of "light" chain protein). High amounts of myeloma protein can damage the kidneys.
Unfortunately, these antibodies aren't helpful in fighting off infection, despite the fact that antibodies are an important part of the immune system. In fact, the myeloma cells can grow so much in the bone marrow that they can push aside the cells that normally grow there, including red blood cells (which is why anemia is a common sign), other white blood cells (making infection more likely) and platelets (bleeding can become a problem).
Like many cancers, myeloma can progress from a more benign condition -- in this case, monoclonal gammopathy of uncertain significance. Not all people with MGUS progress to myeloma, but the condition needs to be carefully watched. Once it becomes myeloma, treatment, usually chemotherapy, is recommended. Multiple myeloma is a highly variable disease, and its prognosis depends on many factors; some come from blood testing, some from the bone marrow biopsy, and some are based on your husband's overall health. Your husband's hematologist/oncologist can give a better estimate of his prognosis based on these factors.