A Critical Appraisal of the Human Tumor Stem-Cell Assay

Abstract

THE "human tumor stem-cell assay" has been proposed as an in vitro method by which anticancer drugs can be selected for activity against tumor cells from a patient. The method is analogous to sensitivity testing for antibiotics in patients with bacterial infection.1 Indeed, the assay is now marketed as a service to practicing oncologists, and advertisements for it have been displayed prominently in this and other journals. We believe that the ability to generate colonies in culture from cells of human tumors represents a major advance in the study of human tumor biology, but the following discussion suggests that its . . .