Problems of dose-response studies in chemical carcinogenesis with special reference to N-nitroso compounds.

Dose-response studies in chemical carcinogenesis are a valuable method for evaluating the risk involved by a certain carcinogen. This article deals with the methods that are presently applied for dose-response studies. It is emphasized that there are many possible mistakes that are already hidden in the method itself; a critical approach is made to the indicative value of dose-response studies. It is also emphasized that the conclusions which may be drawn from dose-response studies can always only be extrapolative but never mathematically calculable. Finally, some practical examples for dose-response studies with n-nitroso compounds are described.