Induction of oral cavity cancer by 3-diazotyramine, a nitrosated product of tyramine present in foods.

A mutagenic nitrosation product of tyramine, 4-(2-aminoethyl)-6-diazo-2,4-cyclohexadienone (3-diazotyramine, 3-DT) preferentially induced tumors of the oral cavity. Squamous-cell carcinomas of the mucosa of the oral cavity floor developed in 19 out of 28 male F344 rats administered 0.1% 3-DT in their drinking water. Tyramine and nitrite are found at fairly high concentrations in various foods. This demonstration of the carcinogenicity of 3-DT indicates that although the implications of 3-DT for human cancer are not clear, other nitrosable mutagen precursors need to be tested as possible risk factors in human cancer.