Treating Oncologic Disease

Abstract

The cancer stem cell hypothesis has become popular in the past few years, in part to provide an explanation of the recurrence of the disease following initial remission and apparent cure. Nevertheless, the concept that cancer is a developmental disease resulting from aberrant control of cellular differentiation is old and is epitomized by teratocarcinomas, a form of testicular germ cell tumor, and by the hematological malignancies. These ideas have developed in parallel with the notion of tissue stem cells that provide for the replacement of functional cells in adult tissues, especially in those tissues subject to continual ‘wear and tear’ throughout adult life. Although a simple view might hold that cancers contain a small population of cancer initiating stem cells equivalent to and, perhaps, derived from the stem cells of the tissue from which they arise, the circumstances of such cancer stem cells is inevitably very different from those of tissue stem cells. Consequently the possibility that a tumor can be composed entirely of oxymoronic nullipotent stem cells is still compatible with a stem cell view of cancer initiation and progression. This review considers the origins of the cancer stem cell concept, and issues that need to be addressed to enhance its utility for developing methods for preventing and treating cancer.