Acute Myeloid Leukemia in Older Patients: Special Problems and Possible Solutions

The median age of patients with newly diagnosed acute myeloid leukemia (AML) in the United States is approaching 70 years. It affects 2.7 per 100,000 individuals in the United States each year and from 0.3 to 5.3 per 100,000 persons around the world. Acute myeloid leukemia in older patients presents special problems because of patient characteristics and the unique biologic behavior of the leukemic cells in this patient population. Older patients tend to have comorbid conditions that compromise cardiac, pulmonary, renal, hepatic, and other organ functions, thereby reducing their ability to tolerate optimal doses of chemotherapy. Many of these patients never make it to a specialist or enter into clinical trials. The leukemic cells in older patients with AML tend to be more resistant to conventional chemotherapeutic agents because of a variety of factors, eg, higher incidence of poor prognostic chromosomal abnormalities, increased expression of multi-drug resistance compared with younger patients. Many of these patients have pre-existing myelodysplastic syndrome which also reduces the ability to achieve and maintain remission following anti-leukemic therapy. Most elderly patients are candidates for investigational therapies because outcome with standard therapies is unsatisfactory.