Predominant Role of Bad Luck of Random Mutations in Cancer

January 12, 2015

Variation in cancer risk among tissues can be explained by the number of stem cell divisions, according to authors of a study published in Science in early January. In an associated media release, the authors highlight that the types of cancer that had a higher risk than predicted by the number of stem cell divisions include skin cancer (linked to sun exposure). Professor Mike Berridge of the Mallaghan Institute provides a helpful commentary on the article in his "Lifestyle sill influence on cancer' opinion piece in the Otago Daily Times.

Abstract

Some tissue types give rise to human cancers millions of times more often than other tissue types. Although this has been recognized for more than a century, it has never been explained. Here, we show that the lifetime risk of cancers of many different types is strongly correlated (0.81) with the total number of divisions of the normal self-renewing cells maintaining that tissue's homeostasis. These results suggest that only a third of the variation in cancer risk among tissues is attributable to environmental factors or inherited predispositions. The majority is due to "bad luck," that is, random mutations arising during DNA replication in normal, noncancerous stem cells. This is important not only for understanding the disease but also for designing strategies to limit the mortality it causes.

Sources:

Tomasetti, C and Vogelstein, B. Variation in cancer risk among tissues can be explained by the number of stem cell divisions. Science 2 January 2015: Vol. 347 no. 6217 pp. 78-81. DOI: 10.1126/science.1260825
http://www.sciencemag.org/content/347/6217/78.abstract?sid=1ea31dce-91b0-4640-ab50-47909862502c

Johns Hopkins media release: http://www.hopkinsmedicine.org/news/media/releases/bad_luck_of_random_mutations_plays_predominant_role_in_cancer_study_shows

See also:
Lifestyle still influence on cancer – Professor Mike Berridge, Otago Daily Times – 15 January 2015
http://www.odt.co.nz/opinion/opinion/330040/lifestyle-still-influence-cancer