Empirical Observations in Support of Carcinogenic Promotion as a Tool for Screening and Regulation of Toxic Agents

摘要

Carcinogens influence both the initation of abnormal cell phenotypes and the subsequent promotion of such cells into a tumor. Certain other agents act as stimulators of proliferation and may have only properties of promotion. Simple examples include mechanical and certain chemical wounding of tissue that results in healing. In addition, hyperplastic growth stimulated by certain chemicals may also promote cancer. Quantification of a hyperplastic condition, or of the body's attempts to heal by the replacement of cells, and a quantification of cells dying from attrition seem necessary but not totally sufficient to explain incidence and latency periods. Empirical relationships between incidence of cancer and estimated cell proliferation in excess of normal will be described. (ERA citation 06:001391)