According to results published in the Journal of Clinical Oncology, treatment with standard-dose chemotherapy resulted in similar outcomes to treatment with high-dose chemotherapy and autologous stem cell transplantation in patients with multiple myeloma.
Multiple myeloma is a cancer of the blood that affects the plasma cells. Plasma cells are an important part of the immune system; they produce antibodies to help fight infection and disease. Multiple Myeloma is characterized by an excess production of abnormal plasma cells. Symptoms include increased risk of bacterial infections and impaired immune responses.
Myeloma may also damage the kidneys and cause osteoporosis, anemia, and an elevated blood calcium level.
In a stem cell transplant, high doses of therapy are used to kill more cancer cells than conventional doses. Unfortunately, the higher doses tend to destroy important hematopoietic stem cells (immature blood cells). These stem cells mature into the following: red blood cells, which transport oxygen and nutrients to tissues in the body; white blood cells, which help the body fight infection; and platelets, which aid the blood in clotting. Low levels of hematopoietic stem cells caused by high-dose treatment can result in life-threatening conditions.
There are two general types of stem cell transplants: an autologous transplant and an allogeneic transplant. During an autologous transplant, the patients’ own hematopoietic stem cells are collected prior to therapy, frozen, and then re-infused following high-dose treatment. During an allogeneic transplant, hematopoietic stem cells are collected from a donor and infused into the patient.
Researchers affiliated with the Southwest Oncology Group (SWOG), Eastern Cooperative Oncology Group (ECOG), and Cancer and Leukemia Group B (CALGB) conducted a clinical trial directly comparing standard dose chemotherapy to high-dose chemotherapy plus radiation therapy followed by an autologous stem cell transplant.
Patients from both treatment groups who achieved anticancer responses were then randomly selected to receive either further treatment with interferon (an agent that stimulates the immune system to fight cancer) or no further treatment.
With a median follow-up of 76 months, outcomes were similar between the groups of patients treated with either standard-dose or high-dose therapy:
- Rates of progression-free survival at 7 years were nearly the same between the two groups of patients: 17% for those treated with high-dose therapy and 16% for those treated with standard doses.
- Rates of overall survival at 7 years were 37% for patients treated with high-dose therapy, compared with 42% for those treated with standard-dose therapy.
- Among patients treated with standard-dose therapy who had a cancer recurrence, those who underwent a subsequent autologous stem cell transplant had a median survival time of 30 months, and those who underwent further standard-dose therapy had a median survival time of 23 months.
- Treatment with interferon did not benefit patients.
The researchers concluded that high-dose therapy and an autologous stem cell transplant does not appear to provide superior results to standard-dose therapy in the treatment of multiple myeloma. These results, however, are conflicting with results from other previous studies indicating improvements in outcomes with the use of high-dose therapy. Furthermore, recent results now indicate that double transplants, including two autologous or an autologous and an allogeneic transplant, appear to provide greater benefit than a single transplant for the treatment of this disease.
It is important for patients with multiple myeloma to speak with their physician regarding their individual risks and benefits of all treatment options for their disease.
Reference: Barlogie B, Kyle R, Anderson K, et al. Standard Chemotherapy Compared With High-Dose Chemoradiotherapy for Multiple Myeloma: Final Results of Phase III US Intergroup Trial S9321. Journal of Clinical Oncology. 2006; 24: 929-936.