Fifty years of clinical research by the leukemia committee of the cancer and leukemia group B.

Progress in the care of patients with leukemia has been one of the great success stories in the field of oncology, and clinical research in leukemia has been the "flagship" of the Cancer and Leukemia Group B since the inception of this organization. Lessons learned from the founders' emphasis on childhood and adult leukemia have been extended broadly over the past 50 years to virtually all types of malignant diseases, and the Leukemia Committee has continued to provide leadership and key contributions. The Leukemia Committee is focused on the individualization of treatment based on distinctive biological and clinical characteristics with the aim of increasing efficacy and decreasing nonspecific toxicity. Our clinical trials in leukemia and myeloma have shifted from primarily empirically derived comparisons of different chemotherapeutic regimens to testing novel concepts such as the role of dose intensity, inhibition of specific mechanisms of drug resistance, the use of hematopoietic growth factors and monoclonal antibodies, and the utility of targeted agents. The Cancer and Leukemia Group B was the pioneer among the cooperative groups in the creation of centralized tissue repositories and the incorporation of correlative laboratory studies as an integral feature of clinical trials, a practice now termed "translational research." Considerable effort has focused on the identification of important pretreatment characteristics, such as morphologic features, immunophenotype, chromosomal abnormalities, and molecular defects, which are significantly associated with outcome in multivariable analyses and which enhance our understanding for the complex biology of these diseases.