According to results recently presented at the 43rd annual meeting of the American Society of Hematology, evidence suggests that consolidation therapy prior to autologous stem cell transplantation may improve outcomes of acute myeloid leukemia (AML) patients with favorable cytogenetics.
Acute myeloid leukemia is a malignant disease or cancer of the bone marrow and blood characterized by the rapid uncontrolled abnormal growth of immature white blood cells known as myelocytes. The disease is more common in adults than in children, with the average age at diagnosis being more than 65 years. However, diagnosis and treatment of children and adults are similar. A majority of patients with AML will die within 2 years of diagnosis. Therefore, researchers are continually developing and exploring new treatments for AML in order to improve upon survival for these patients. Treatment involves induction therapy (initial treatment given to induce a remission) followed by consolidation therapy (treatment following induction therapy).
In order to understand the best treatment options available for AML, the classification or histologic (cellular) subtype must be identified. In addition, analyses of chromosomes by cytogenetic examination must be performed. These are tests performed on a sample of the bone marrow. Cytogenetics is the process of analyzing the number and shape of chromosomes (the arrangement of genetic material into 46 structures found in every cell). Acute myeloid leukemia is frequently associated with abnormal chromosomes of the leukemia cells. Previous research has defined some of the karyotypes (the arrangement of chromosomes) of leukemia cells that put a patient at a low, intermediate or high risk for cancer progression or relapse following therapy. Thus, knowing the specific chromosomal abnormalities associated with leukemia is becoming more important for determining appropriate treatments.
A multi-institutional clinical trial was recently conducted to evaluate the impact of consolidation therapy prior to autologous transplantation on various karyotypes in patients with AML. The trial involved 81 patients who were divided into two groups according to cytogenetics. The two groups included patients with favorable cytogenetics (t(8;21), inv(16), t(15;17)) and patients with all other chromosomal abnormalities. All patients first received induction therapy and then consolidation with zero, one, or two or more cycles of chemotherapy prior to transplant. In the group of patients with favorable cytogenetics, the rate of cancer recurrence three years following therapy was 100% for those receiving no consolidation therapy, 64% for those receiving one cycle and 9% for those receiving two or more cycles. In the group of patients with all other chromosomal abnormalities, the rate of cancer recurrence three years following therapy was 100% for those receiving no consolidation therapy, 43% for those receiving one cycle and 40% for those receiving two or more cycles.
The researchers conducting this clinical trial concluded that additional consolidation improves outcomes for patients with AML with favorable cytogenetics undergoing an autologous stem cell transplant. However, the benefit of more than one cycle of consolidation for patients with other cytogenetics is not clear. Future studies may further define an improved approach for consolidation therapy in patients with other cytogenetics.
Patients with AML may wish to speak with their physician about the risks and benefits of participating in a clinical trial further evaluating the efficacy of intensified consolidation therapy as well as other novel approaches. Two sources of information regarding ongoing clinical trials include comprehensive, easy-to-use listing services provided by the National Cancer Institute (
Proceedings from the 43rd annual meeting of the American Society of Hematology, abstract # 2993, Orlando, Florida, December 11-14, 2001)