LETTER

Debunking mathematically the logical fallacy that cancer risk is just “bad luck”

Department of Management, Technology and Economics, ETH Zürich (Swiss Federal Institute of Technology), Scheuchzerstrasse 7, Zürich, CH-8032, Switzerland

^* e-mail: maroussiafavre@ethz.ch

Received: 24 September 2015
Accepted: 30 October 2015
Published online: 1 December 2015

Abstract

Tomasetti and Vogelstein recently proposed that the majority of variation in cancer risk among tissues is due to “bad luck,” that is, random mutations arising during DNA replication in normal noncancerous stem cells. They generalize this finding to cancer overall, claiming that “the stochastic effects of DNA replication appear to be the major contributor to cancer in humans.” We show that this conclusion results from a logical fallacy based on ignoring the influence of population heterogeneity in correlations exhibited at the level of the whole population. Because environmental and genetic factors cannot explain the huge differences in cancer rates between different organs, it is wrong to conclude that these factors play a minor role in cancer rates. In contrast, we show that one can indeed measure huge differences in cancer rates between different organs and, at the same time, observe a strong effect of environmental and genetic factors in cancer rates.