[Introduction of medium-term skin carcinogenicity testing using mice]

We will begin accepting orders for medium-term skin carcinogenicity testing from this fiscal year, .

The medium-term carcinogenicity test (two-stage carcinogenicity model) is a test method specified as an "in vivo additional test for detecting carcinogenicity" in the Ministry of Health, Labor and Welfare's "Guidelines for Carcinogenicity Testing of Pharmaceuticals."

In the medium-term carcinogenicity test, 7,12-Dimethylbenz[a]anthracene (DMBA), a skin carcinogen, is applied once to the back skin of mice to initiate cell mutation (initiation), and the number and size of skin tumors that develop are measured after applying the test substance for 19 weeks starting one week later. Histopathological examination is then performed to confirm the promotion effect on the skin and predict the carcinogenicity of the administered test substance.