The Syrian hamster embryo cells transformation assay identifies efficiently nongenotoxic carcinogens, and can contribute to alternative, integrated testing strategies

• Pre-screening for carcinogenicity may fail to identify nongenotoxic carcinogens.
• Nongenotoxic carcinogens are up to 25% of recognized human carcinogens.
• The SHE transformation assay identifies 80–90% of nongenotoxic carcinogens.
• The SHE assay can contribute to integrated testing strategies.

The long-term carcinogenesis bioassays have played a central role in protecting human health, but for ethical and practical reasons their use is dramatically diminishing and the genotoxicity short-term tests have taken the pivotal role in the pre-screening of chemical carcinogenicity. However, this strategy cannot detect nongenotoxic carcinogens. Since up to 25% of IARC human carcinogens are recognized to have nongenotoxic mechanisms of action, the risk they pose to human health cannot be disregarded, and it is urgent to fill the gap in the tools for alternative testing.In this paper, we analyze from different perspectives the ability of Cell Transformation Assays to identify nongenotoxic carcinogens, and we conclude that the Syrian hamster embryo cells test is able to identify nongenotoxic carcinogens with 80–90% efficiency, and thus, can play an important role in integrated, alternative testing strategies.