The Significance and Interpretation of in Vitro Carcinogenicity Assay Results

Abstract

The major implication of discovering a new chemical carcinogen, whether synthetic of natural, is that it may present a carcinogenic risk to exposed populations. Only in cases where significant manufacturing or environmental human exposure to that chemical exists will a possible human carcinogenic hazard exist. It is therefore desirable that a system of hazard assessment should be devised. The above approach assumes that chemical carcinogens are easily and clearly definable — but such, of course, is not the case. One of the major causes of confusion in this area is the fear felt by many that insufficient or circumstantial evidence of carcinogenicity will be used to stimulate the response usually reserved for established human carcinogens. For example, few people would disagree with attempts to remove a recognizable source of potential hazard, such as the presence of a potent animal carcinogen in drinking water, but many would question whether abrupt action should be taken on finding that hamburgers contain chemicals mutagenic to S. typhimurium.