Acute myeloid leukemia in the elderly: biological features and search for adequate treatment.

AML in elderly patients is a heterogeneous disease which is characterized by a number of unfavorable features such as development, cytogenetics, blast cell differentiation, and poor treatment response. Specifically, the association between a higher incidence of unfavorable cytogenetic abnormalities in elderly patients and poor prognosis has been well documented. Low treatment response may be due to the specific biology of AML in this patient group, but also to host-specific factors such as higher treatment-related morbidity and mortality. Treatment tolerance cannot be judged on grounds of chronological age alone; risk factor analysis with regard to performance status, organ function, and underlying systemic disease need to be considered as well. For effective induction treatment in elderly patients, instant and intensive chemotherapy appears to be necessary, while delayed treatment or administration of supportive care alone provide unsatisfactory results. Standard-dose ara-C/anthracycline-containing regimens are the treatment of choice in patients with good performance status. However, patients with a WHO grading of greater than 3 might rather benefit from reduced regimens such as low-dose ara-C. At present, greatest improvement of AML treatment in elderly patients can be expected from an improvement of supportive care.