Trichloroethylene: Using New Information To Improve the Cancer Characterization

The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency. Assessments of TCE's potential to cause cancer in humans have had to address issues concerning the strength of the human evidence and the relevance of the animal tumors to humans. The epidemiological database now includes analyses of multiple studies and molecular information. A recent analysis strongly suggests that TCE may induce cancer in humans at multiple sites, including kidney, liver, and lympho-hematopoietic cancer. Molecular analyses have found mutations of the von Hippel-Lindau tumor suppressor gene in renal tumors of TCE-exposed individuals. The animal bioassays have been followed up with mechanistic studies that provide insight into TCE's possible modes of action at each tumor site. This information suggests that TCE may act through mechanisms that can be relevant to human cancers. The mechanistic information can also be used to identify risk factors that may make some people more susceptible to TCE's adverse effects, allowing a fuller characterization of TCE's cancer potential in different groups of people.