Multiple myeloma is a cancer of the plasma cells, a type of immune cells that produce antibodies to fight infection. Plasma cells are found in the bone marrow, the “blood factory” found within the hollow area of bones. Because plasma cells are found in the blood, myeloma is referred to as a hematologic or blood cancer.
When a patient has multiple myeloma their plasma cells reproduce uncontrollably. As a result the plasma cells crowd out other types of blood cells that are essential to be healthy such as red blood cells or platelets, weakening the immune system. Also, too much monoclonal protein (M-protein) is produced. High levels of M-protein levels are a key indicator of multiple myeloma.
The first line diagnosis for multiple myeloma is identifying an excess of M-protein in the blood and elevated levels of plasma cells in the bone marrow with a blood test.
Confirmation and analysis of the disease is followed up by one of two invasive procedures, bone marrow aspiration or bone marrow biopsy. Both involve inserting large, long needles into the bone and drawing samples of the bone marrow.
There are approximately 32,000 new cases of multiple myeloma in the US per year, and it has a prevalence of approximately 140,000 cases at any one time. The five-year survival rate is 54%.
Patients typically build up resistance to combination therapies and have to switch multiple times over the course of the disease. Common symptoms include; bone pain, nausea, constipation, fatigue, weight loss and frequent infections.
There are precursors to active multiple myeloma; the earliest is called monoclonal gammopathy of undetermined significance (MGUS). It is characterized by an excess of M-proteins in the blood, however it is benign and asymptomatic. MGUS occurs in 3–4 % of people over the age of 50, although only 1% of patients with MGUS will advance to active multiple myeloma each year.
Smoldering multiple myeloma (SMM) is an intermediate step between MGUS and active multiple myeloma. SMM is diagnosed when patients have an excess of M-protein in the blood and elevated level of plasma cells in their bone marrow. SMM is also asymptomatic. There are approximately 250,000 people with SMM in the US and 10 – 15 % will advance to active multiple myeloma within 5 years.
There are currently no diagnostic or prognostic tests that accurately identify the high-risk SMM patients likely to transition to active multiple myeloma.
Industry is turning towards identifying patients in the high-risk category of SMM for earlier treatment to delay the onset of active multiple myeloma and its debilitating symptoms.