N-nitroso compounds and tobacco-induced cancers in man.

Human exposure to N-nitroso compounds in tobacco products is more intense and widespread than from any other known source. This paper presents evidence that two of these N-nitroso compounds, 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone and N'-nitrosonornicotine are involved in causing cancers of the oral cavity, lung, oesophagus and pancreas in tobacco users. The reduction or elimination of these nitrosamines from tobacco products would probably lead to a decrease in the incidence of these cancers.