Related Experiment Video
Updated: Aug 8, 2026
17:28
Human Pluripotent Stem Cell Based Developmental Toxicity Assays for Chemical Safety Screening and Systems Biology Data Generation
Published on: June 17, 2015
Lessons learned in applying the U.S. EPA proposed cancer guidelines to specific compounds
M E Andersen1, M E Meek, G A Boorman
1Department of Environmental Health, Colorado State University, Fort Collins, USA.
Summary
The U.S. EPA
Area of Science:
- Environmental toxicology
- Risk assessment science
Background:
- The U.S. Environmental Protection Agency (EPA) developed proposed guidelines for carcinogen risk assessment.
- An expert panel evaluated these guidelines using data for chloroform (CHCl3) and dichloroacetic acid (DCA).
Purpose of the Study:
- To assess the strengths and limitations of the proposed EPA carcinogen risk assessment guidelines.
- To provide recommendations for improving the quantitative aspects of the guidelines.
Main Methods:
- Expert panel review of proposed EPA guidelines.
- Application of guidelines to specific chemical data sets (chloroform and dichloroacetic acid).
Main Results:
- The panel found the proposed guidelines a significant improvement, offering flexibility and incorporating state-of-the-art science.
- Key areas for improvement include criteria for mode of action determination and quantitative risk assessment methods.
Conclusions:
- The proposed guidelines are a valuable template for carcinogen risk assessment, promoting harmonization.
- Further development is needed for quantitative implementation, particularly regarding mode of action and margin of exposure calculations.
Related Concept Videos
02:59Cancer Prevention
Several factors can increase the risk of cancer in an individual. About 50% of cancer cases can be prevented by adopting a healthy lifestyle, regular exercise, eating healthy, and following a modest cancer prevention diet. Epidemiological studies have consistently shown that populations with vegetable and fruit-rich diets have reduced the incidence of cancer. On the other hand, populations who have a diet rich in animal fat, red meat, junk food, or high calories are predisposed to cancer.
Some...
Some...
02:50Combination Therapies and Personalized Medicine
Combining two or more treatment methods increases the life span of cancer patients while reducing damage to vital organs or tissue from the overuse of a single treatment. Combination therapy also targets different cancer-inducing pathways, thus reducing the chances of developing resistance to treatment.
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...
01:25Mutagenicity and Carcinogenicity
Mutagenicity and carcinogenicity refer to the ability of drugs to cause genetic defects and induce cancer, respectively. The International Agency for Research on Cancer (IARC) classifies agents into four groups based on their carcinogenic potential. Group 1 agents are known human carcinogens; group 2A agents are probably carcinogenic to humans; group 3 agents lack data to support their role in carcinogenesis; and group 4 includes agents for which data support that they are not likely to be...
01:11Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
01:23Toxicity Testing in Animals
Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence...
01:21Cancer Survival Analysis
Cancer survival analysis focuses on quantifying and interpreting the time from a key starting point, such as diagnosis or the initiation of treatment, to a specific endpoint, such as remission or death. This analysis provides critical insights into treatment effectiveness and factors that influence patient outcomes, helping to shape clinical decisions and guide prognostic evaluations. A cornerstone of oncology research, survival analysis tackles the challenges of skewed, non-normally...