Variation in cancer risk among tissues can be explained by the number of stem cell divisions

TLDR

Certain human tissues exhibit vastly different cancer incidence rates, prompting investigation into underlying causes. The authors plotted lifetime cancer incidence against estimated normal stem cell divisions per tissue, revealing a strong correlation across five orders of magnitude. They concluded that the number of stem cell divisions explains most of the variation in cancer risk, with random replication errors contributing more than hereditary or environmental factors. Published in *Science*, issue p.

Abstract

Crunching the numbers to explain cancer Why do some tissues give rise to cancer in humans a million times more frequently than others? Tomasetti and Vogelstein conclude that these differences can be explained by the number of stem cell divisions. By plotting the lifetime incidence of various cancers against the estimated number of normal stem cell divisions in the corresponding tissues over a lifetime, they found a strong correlation extending over five orders of magnitude. This suggests that random errors occurring during DNA replication in normal stem cells are a major contributing factor in cancer development. Remarkably, this “bad luck” component explains a far greater number of cancers than do hereditary and environmental factors. Science , this issue p. 78