Effect of age on survival in acute leukemia. 1950-1990

Four decades ago, survival of patients with acute leukemia was brief at any age. Since 1950, survival of children has increased remarkably but has changed little for the elderly. The nature and magnitude of this age difference in survival are not understood.

Median survival was determined in 2364 Kansas residents diagnosed with acute leukemia from 1947 until 1990. Of this number, 1032 had acute lymphocytic leukemia and 1227 had acute myelocytic leukemia diagnosed between 1950 and 1989. These patients were stratified by age and decade of diagnosis. Survival was computed by life-table analysis with significance determined by log-rank, Wilcoxon, and Fisher exact tests.

During the 40 years of the study, highly significant increases occurred in median survivals for all groups with either acute lymphocytic leukemia or acute myelocytic leukemia occurring in patients younger than 60 years of age (P < 0.0001 for some age groups), but no significant increases for those 61 to 80 years of age and those 81 years of age and older. Viewed in another dimension, for each decade from the 1960s to the present in acute lymphocytic leukemia and from the 1970s to the present in acute myelocytic leukemia, age at diagnosis was inversely correlated with median survival in a highly significant manner (P < 0.001).

Increasing age is inversely related to survival in patients with acute leukemia. The lack of significant improvement in median survival in the last 40 years for those older than 60 years of age stands in stark contrast to the remarkable improvement for younger patients. Acute leukemia in older patients demands new and probably different therapeutic strategies.