DNA in cancerous tissues of tobacco smokers shows mutation patterns that differ from those in cancerous tissues of nonsmokers, a new analysis finds. The new study, in the Nov. 4 Science, reveals how smoking contributes to different cancers, enhancing several kinds of DNA damage.
“We are doing a sort of molecular archaeology,” says cancer geneticist Ludmil Alexandrov of Los Alamos National Laboratory in New Mexico, who led the analysis. While smoking’s link to cancer has been known for decades, “it’s always been a bit of a mystery why smoking increases the risk of cancers like bladder or kidney — tissues that aren’t exposed to smoke.”