Multiple myeloma: A rapid review

In the Rapid Review series, I briefly review the key points of a clinical review paper or two. The topic: Multiple Myeloma

The papers: 

Nau KC, Lewis WD. Multiple myeloma: diagnosis and treatment. Am Fam Physician. 2008 Oct 1;78(7):853-9. PMID: 18841734

Eslick R, Talaulikar D. Multiple myeloma: from diagnosis to treatment. Aust Fam Physician. 2013 Oct;42(10):684-8. PMID: 24130968

What is it?

Multiple myeloma is a malignancy of the bone marrow plasma cells, which secrete abnormal antibodies, or fragments of antibodies.

How does it present?

Patients often present with unexplained back pain or bone aches. A pathologic fracture will be the presenting symptom in about 25% of patients. In other words, this is a disease that needs to be on the emergency clinician’s radar.

Patients will also commonly have anorexia, nausea, somnolence, weakness, and/or malaise. (This sounds a bit like a needle in a haystack among my elderly patients). Polydipsia, anemia, and hypercalcemia might be more specific findings. Some less common presentations include recurrent bacterial infections from relative immunosuppression and neurologic symptoms from hyperviscosity.

It is also important to note that 34% of patients are asymptomatic at presentation, with incidental findings of hypercalcemia, renal impairment, or elevated protein on bloodwork leading to the diagnosis.

What are smouldering myeloma and MGUS?

Smouldering myeloma is the term used for asymptomatic patients with testing consistent with multiple myeloma. MGUS stands for monoclonal gammopathy of undetermined significance and is also an asymptomatic laboratory finding. Both are asymptomatic, and neither need treatment, but follow-up is important as there is about a 10% risk of progression to multiple myeloma per year.

Who should get worked up?

The recommendation is a workup for elderly patients with bone or back pain and fatigue that hasn’t resolved with 2-4 weeks of symptomatic therapy. Seeing as almost all back pain lasts longer than 2-4 weeks, practically speaking this is going to mean screening most elderly patients with back pain.

How is it worked up?

The test for multiple myeloma is serum and urine protein electrophoresis.

Tests that can be helpful when screening the very broad population that has the non-specific symptoms associated with multiple myeloma include a complete blood count, creatinine, calcium level, and x-rays (for multiple lytic lesions).

What is the treatment?

There is not much to do in the emergency department, aside from treating the patient’s presenting complaint and managing hypercalcemia or acute renal failure (if present). Renal impairment is very common, and so NSAIDs should be avoided (which is important as pain is the most common presenting complaint). Patients will get an oncology referral. Many patients (those without symptoms) are not treated at all, as earlier treatment does not improve mortality but does increase the risk of acute leukemia. 

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