Background : Staging : Treatments : Summary

Background

Multiple myeloma is a malignancy caused by the unregulated proliferation of a population of plasma cells in the bone marrow.  Plasma cells are part of the normal immune system.  Their primary purpose is the production of normal immunoglobulins or antibodies which are produced in response to infections, inflammation, and even malignancies.  These plasma cells are normally well regulated and can be thought of as small factories for immunoglobulins.  The typical signs and symptoms of multiple myeloma relate to the loss of normal bone marrow function and weakening of the bone itself. 

Epidemiology

Multiple myeloma represents approximately 1% of all new cases of cancer identified annually.  It does account for approximately 13% of all blood related malignant disorders in the United States.  There is a slightly higher incidence rate in African-Americans and in males.  The average age of patients presenting at diagnosis is 63 years.  There is a slight increased incidence as age increases.  Studies have shown an increased prevalence in patients who have been exposed to fuel oil products, agricultural workers, miners and sheet metal workers.  The specific etiologic factors regarding multiple myeloma are unknown. 

Signs and Symptoms

The most common presenting complaint in multiple myeloma is bone pain relating to the destruction of the bone by the myeloma plasma cells.  Other common symptoms include:  fatigue, increased incidence of infection and bruising or easy bleeding.  Signs of the disease include: anemia, abnormal bone x-rays, abnormal findings of protein in the blood or urine, and kidney dysfunction. 

Diagnostic tests

Studies which are indicated in patients who have multiple myeloma should include: Complete blood counts, blood chemistry studies, uinalysis, specific immunoelectrophoretic studies of blood and urine, x-rays of the spine, skull and long bones, and a bone marrow aspirate and biopsy examination.  Other studies may be taken from the bone marrow which may be used to help identify certain prognostic categories in myeloma patients.  Further imaging studies such as MRI or CT scans may be indicated to identify causes of atypical pain or neurologic symptoms.

Staging of multiple myeloma

Although staging malignancies is an important part of developing therapeutic strategies for many malignancies, staging has not been as significant in determining therapy for multiple myeloma.  Localized myeloma (solitary plasmacytomas) are most typically treated with radiation therapy alone and followed carefully.  However, in true multiple myeloma staging has been used to help in determining prognosis and at times the aggressiveness of therapy.  The most typical staging system utilized is called the Durie-Salmon staging system. Different signs of disease such as anemia, calcium level, kidney function and degree of bone disease are used to determine the stage at presentation or at original diagnosis.  The staging for multiple myeloma can be developed from the basic studies performed during the diagnostic evaluation. 

Treatment alternatives

Unlike certain malignancies the rationale for therapy of multiple myeloma is based upon the signs, symptoms and laboratory results found at the time of diagnosis more so than simply making the diagnosis.  Although timing of treatment for multiple myeloma may be variable, and dependent upon the strategy agreed upon between the patient and treating physicians, the principal form of therapy utilized in this disease is chemotherapy.  As in most malignancies there have been a variety of treatment programs which have been utilized and studied in attempts to improve the overall response and survival in this disease process.  The determination of treatment is usually based upon age, underlying health, specific laboratory results and symptoms.  The treatment may include what one could consider standard oral treatment with Melphalan and Prednisone, or move to an aggressive form of therapy such as/or including bone marrow transplantation.  A number of cooperative cancer study groups throughout the world are continuing to try to develop improved treatment programs. 

When determining the appropriate treatment for multiple myeloma your hematologist/oncologist will likely have reviewed the concerns regarding treatment of smoldering myeloma, indolent myeloma versus active disease.  By close monitoring of the disease process appropriate therapy can be determined and initiated at the proper time.  As one would expect different drug regimens may have different side effects or concerns and are better reviewed in a more specific drug related discussion.

Radiation therapy can be an important part of the treatment program available for multiple myeloma patients.  The role of radiation therapy may include those instances of solitary plasmacytoma of bone, osteosclerotic myeloma, relief of spinal cord or nerve root compression, prevention of pathologic fractures, and palliation of pain due to localized tumor growth.  In each of these instances radiation can be provided in such a way as to effectively eradicate the disease at the site of radiation, but may not have significant impact upon the systemic process requiring chemotherapy.  In treatment programs utilizing aggressive types of therapy such as stem cell treatment or bone marrow transplantation more sophisticated and systemic radiation therapy may be utilized.  Side effects of the radiation tend to be limited, especially because of the localized nature of most of the therapeutic programs.  Blood counts may be affected in patients receiving radiation therapy, even if they are not receiving chemotherapy at the same time.  Close observation may be indicated depending upon the circumstances of therapy. 

Summary

Multiple myeloma is a relatively rare malignancy which results in systemic symptoms and frequently local bone disease.  As a general statement, active multiple myeloma is best treated with systemic chemotherapy programs but may be benefitted by the addition of radiation therapy in circumstances as noted above.  Your hematologist/oncologist or radiation oncologist will be able to give more specific information in regard to treatment programs, side effects and response. 

John Garton, MD