On the etiology and pathogenesis of the leukemias: a review.

Abstract

Summary 1.The incidence of leukemia appears to be increasing rapidly. 2.The leukemias probably do not all have the same etiology, although the mechanisms by which the various forms arise may well have much in common. 3.To account for the bulk of human leukemias, it would seem necessary to widen our horizons beyond such agents as radiation and benzol and to look with suspicion as a possible inciting agent on any chemical, drug, or body reaction, such as hypersensitivity, which is capable of causing severe injury to hematopoietic tissue. 4.We are in need of additional careful studies of the preleukemic phase, as well as of the epidemiology of the leukemias; the fragmentary information now available indicates that the leukemias do not spring abruptly from previously normal tissues but burst into flame, as it were, from a smoldering pre-existent hematopoietic disorder of varying origin and morphology. 5.Whereas most human evidence pertains to myelogenous leukemia, experimental work to date has been primarily concerned with lymphatic leukemia and lymphosarcoma. The evidence reviewed established the fact that the induction mechanism is an indirect process reflecting the complex interrelationship of multiple factors. A hypothesis has been suggested which is consistent with this evidence and which implicates a chronic disturbance of normal tissue growth equilibrium as the major factor in leukemogenesis.