Multiple myeloma is a cancer of the plasma cells--white blood cells that are located in the bone marrow. The term multiple myeloma is used because the cancer occurs at more than one site in the bones. There are several variants of multiple myeloma, with early or indolent types requiring only scheduled checkups, while advanced forms mandate prompt treatment.
Smoldering Myeloma
Smoldering myeloma, also called indolent myeloma, is an asymptomatic cancer characterized by small increases of the M protein in the blood and of M plasma cells in the bone marrow. The levels of these markers are lower than those in active multiple myeloma. Smoldering myeloma develops slowly and, as there are no bone tumors or damage to the body, the recommended treatment is watchful observation. Researchers are studying genes from patients with this condition to help define who is most likely to progress to active myeloma.
Solitary Plasmocytoma
Unlike standard multiple myeloma, which is characterized by tumors at many sites in the bones, solitary plasmocytoma is only one tumor, typically in a bone. According to the American Cancer Society, this type of myeloma responds well to treatment, usually radiation and/or surgery, which can be curative. Because patients with solitary plasmocytomas of the bone have a higher risk for multiple myeloma, they must be monitored closely at regular intervals.
Stage I Myeloma
Stage I multiple myeloma is early disease with symptoms, such as damage in one bone. Like smoldering myeloma, it is slowly progressing or stable. According to the Multiple Myeloma Research Foundation, patients should get a checkup every three months, with treatment started only if their disease progresses.
Active Myeloma
Stage II and III multiple myeloma is active cancer that has advanced, with more myeloma cells throughout the body than with indolent forms. Patients exhibit a variety of symptoms. Active myeloma has high levels of M protein, the characteristic marker for myeloma. Because stage II and III myeloma may progress rapidly, immediate treatment is mandated.
Link With MGUS
According to the Mayo Clinic, multiple myeloma often begins as monoclonal gammopathy of undetermined significance, or MGUS, a benign condition affecting about 3 percent of people over 50 years old in the United States. Each year, 1 percent of this group develops full-blown multiple myeloma. Their risk remains high, even if they have had MGUS for 25 years. Like multiple myeloma, MGUS is characterized by elevated levels of M proteins and plasma cells, which are genetically similar in the two diseases. However, unlike multiple myeloma, MGUS does not harm the body, and no treatment is required other than watchful observation.
References
- National Cancer Institute. What You Need to Know About Multiple Myeloma
- MayoClinic.com. Multiple Myeloma
- DeVita VT, et al: "Plasma Cell Tumors" in Cancer: Principles & Practice of Oncology. 7th ed. 2005.
- American Cancer Society: Do We Know What Causes Multiple Myeloma
- Multiple Myeloma Research Foundation. Current and Emerging Trends in the Treatment of Multiple Myeloma
