Due to the fact that it is such a rare disease, overall data collection has been relatively sparse, making it difficult to determine biological characteristics of patients and responses to treatments regarding this cancer. Obtaining information to develop statistical associations and trends is important to facilitate the designation of optimal standard treatment. Recently, researchers affiliated with the Eastern Cooperative Oncology Group (ECOG) have compiled and evaluated data involving patients who had been diagnosed with acute megakaryocytic leukemia between 1984 and 1997.
Acute megakaryocytic leukemia is a cancer involving the bone marrow, which is the spongy material inside large bones. The bone marrow produces immature cells that develop into three distinct types of blood cells: red blood cells which carry Oxygen to tissues, white blood cells which fight infection, and platelets which aid in blood clotting. Acute megakaryocytic leukemia is characterized by excessive division and accumulation of immature platelets in the bone marrow. These cancerous cells never develop into functioning platelets, and crowd the bone marrow causing suppression of normal formation and function of other blood and immune cells. In addition, this cancer is often associated with a condition called myelofibrosis, which occurs when fibrous tissue replaces healthy bone marrow. Children with Down syndrome appear to have an increased incidence of acute megakaryocytic leukemia, but have a higher survival rate than other patients diagnosed with this disease.
Researchers from ECOG recently evaluated data from 20 patients diagnosed with acute megakaryocytic leukemia in an attempt to define associations and/or superior treatment strategies. The range of age for these patients was between 18 and 70 years, with the average age being 42.5 years. Myelofibrosis was present in the bone marrow of all patients, with the majority of cases being extensive. Of the patients who underwent genetic studies, the most frequent genetic abnormalities were found on chromosome 3. All patients were treated with a chemotherapy combination consisting of an anthracycline and cytarabine. Complete disappearance of cancer (remission) was achieved in 50% of the patients with the duration of remission lasting 11 months. However, the average overall survival for these patients was approximately 10 months. Although 50% of patients achieved a complete response, the long-term outcome was poor. These results indicate the necessity of focused research efforts and clinical trials aimed at improving treatment of acute megakaryocytic leukemia.
There is still a lot to learn about acute megakaryocytic leukemia, but studies such as these, as well as clinical trials, aid in the future progress of more effective treatments, which potentially lead to increased survival rates. Persons with acute megakaryocytic leukemia may wish to speak with their physicians about the risks and benefits of participating in a clinical trial evaluating stem cell transplantation and other promising new treatment strategies. Two sources of information of ongoing clinical trials that can be discussed with a doctor include comprehensive, easy-to-use services provided by the National Cancer Institute (cancer.gov) and eCancerTrials.com. eCancerTrials.com also provides personalized clinical trial searches on behalf of patients. (Blood, Vol 96, No 7, pp 2405-2411, 2000)