The mysterious steps in carcinogenesis

This is the authors' abstract. We don't add key points for this paper.

The mutational changes needed to create a cancer cell have been itemised in great detail ( Hahn and Weinberg, 2002 ). These mutations are commonly assumed to accumulate over the course of years as a consequence of spontaneous replication errors or, in special cases, the misrepair of DNA lesions introduced by carcinogens such as tobacco smoke or sunlight. Yet, there are numerous discrepancies between the mutagenicity of chemicals and their danger to humans ( Clemmesen and Hjalgrim, 1977 ; Jansen et al, 1980 ; Ames et al, 1987 ), and the time course of carcinogenesis is deeply mysterious. Indeed, we still do not know the proximate causes of most cancers even though these are what we want to learn how to avoid.