Childhood leukemia as a model for cancer research: the Richard and Hinda Rosenthal Foundation Award Lecture.

Childhood acute lymphocytic leukemia (ALL) is a model for the study of disseminated cancer. It is always disseminated and relatively uniform, it is accessible to repetitive tissue sampling, and we have highly effective chemotherapy for it. The first systematic, controlled trials of cancer therapy were designed for patients with ALL by physicians with the courage and audacity to aim for cure of a "hopeless" disease. The concept of leukemia cell subpopulations in each patient received major clinical support from ALL. The pharmacological sanctuary, typified by the meninges, was first discovered and specifically attacked in ALL. Combination therapy, aggressive therapy during remission, phase-specific therapy, and the interrelationships of phases of therapy were developed first in ALL. Since leukemia cell features, such as T-cell characteristics, correlate with responsiveness to therapy, powerful new tools may be developed to improve the biological specifically of therapy. In addition to the gratifying results of therapy over the past two decades, childhood ALL continuity offers opportunities for biological research as well as improved therapy for ALL and other forms of disseminated cancer.