Carcinogen prediction in the laboratory: a personal view.

Area of Science:

• Toxicology
• Chemical carcinogenesis
• Risk assessment

Background:

• Carcinogens encompass viruses, physical agents, and chemicals, with chemicals posing the greatest concern due to their prevalence.
• Current carcinogenicity testing involves lifetime animal studies at high doses, which are economically unfeasible for all human-exposed chemicals.

Purpose of the Study:

• To review and compare traditional carcinogenicity testing methods with novel screening approaches.
• To evaluate the utility of new methods in predicting human cancer hazards from chemical exposure.

Main Methods:

• Review of traditional lifetime rodent bioassays for carcinogenicity.
• Introduction and review of new rapid, cost-effective screening methods for chemical carcinogenicity.
• Focus on the hypothesis that carcinogenic chemicals are electrophiles or become electrophiles through metabolism.

Main Results:

• Traditional methods are resource-intensive and impractical for the vast number of chemicals requiring assessment.
• New screening methods offer a faster and cheaper alternative for evaluating large chemical libraries.
• The electrophilic nature of carcinogens serves as a unifying principle for these new methods.

Conclusions:

• New screening methods hold promise for more efficient and economical prediction of chemical carcinogenicity.
• These novel approaches are crucial for assessing the potential cancer risk posed by widespread chemical exposures to humans.
• Further validation and comparison are needed to fully establish the role of these methods in regulatory toxicology.