Test Identifying Cell Genetic Abnormalities Can Help Predict Survival after Standard-Dose Chemotherapy for Persons with Multiple Myeloma
For persons with multiple myeloma, initial treatment usually consists of standard-dose chemotherapy. However, very high doses instead of standard doses of chemotherapy can result in increased survival time for some persons. Because these high doses of chemotherapy also destroy the young blood cells in the bone marrow a procedure called an autologous stem cell transplantation is also performed to “rescue” the bone marrow and hasten blood cell production. However, this procedure can produce life-threatening complications in some persons; therefore, it is important for doctors to have the ability to identify who is most likely to do well with the standard chemotherapy, and who will benefit most from a more aggressive regimen. Now, researchers in Austria report that they may be able to predict who will respond well or poorly to the standard therapy by identifying certain cell genetic characteristics.
Multiple myeloma, a type of cancer called a plasma cell neoplasm, is characterized by the presence of cancerous plasma cells in the bone marrow. The bone marrow (and circulating blood) contains early blood-forming cells, called stem cells, which grow and mature into the 3 blood cell types: white blood cells (protect the body from infection), red blood cells (carry oxygen to the tissues), and platelets (help the blood to clot). The plasma cells are then produced by a type of white blood cell, called lymphocytes, and serve to protect the body from infection. The cancerous plasma cells can crowd out other cells, such as red blood cells; can cause a breakdown of bone; and can collect to form tumors (called plasmacytomas) in the bone.
Once symptoms of the disease manifest, persons with multiple myeloma are usually treated with standard-dose chemotherapy. The use of high-dose chemotherapy with a stem cell transplantation can offer hope for a prolonged survival time for some patients. Because the high-dose therapy and the transplant procedure can lead to life-threatening complications for some persons, it is important for doctors to be able to identify those for whom standard therapy is likely to be successful. For many types of cancer, including multiple myeloma, there are certain cell genetic abnormalities associated with the disease, and these abnormalities can often be correlated with how the disease will respond to treatment. Austrian researchers recently used a test, called fluorescence in situ hybridization (FISH), to detect the cell genetic abnormalities associated with multiple myeloma and correlated them with how patients with these abnormal cells responded to initial treatment with standard-dose chemotherapy.
The FISH test method was used to detect genetic cell abnormalities in the bone marrow cells of 89 persons with previously untreated multiple myeloma. These individuals then received treatment with standard-dose chemotherapy. Based on the cell genetic abnormalities and treatment outcomes observed, the researchers were able to produce categories as to whether persons are likely to have a good, intermediate, or poor outcome to standard-dose chemotherapy. The group with a good outcome (41%) had an average survival time of more than 8 years. Those in the intermediate outcome group (35%) had an average survival time of 2 years, and those in the poor outcome group (24%) had an average survival time of 1 year.
These findings are important because the cell genetic abnormalities that are found allow doctors to identify persons who are likely to do well or poorly with standard chemotherapy. Doctors can then help patients with multiple myeloma to make a more informed choice about whether to opt for the standard-dose chemotherapy or a more aggressive high-dose chemotherapy regimen with a stem cell transplantation as initial treatment. Persons who are newly diagnosed with multiple myeloma may wish to talk with their doctor about the possible use of the FISH test to help in choosing a treatment, or of participating in a clinical trial in which new therapies are being studied. (Journal of Clinical Oncology, Vol 18, No 4, pp 804-812, 2000)