cancer as someone who has never smoked, but only about 1.5 times as likely to develop liver cancer.
“It is a fairly modest association, but because so many people smoke, it’s still an important cause of these cancers,” said Neal Freedman, an epidemiologist at the National Cancer Institute.
He pointed out that the surgeon general last looked at the effect of smoking on liver cancer in 2004, and found the evidence only suggestive. Since then, 90 new studies have been published allowing the surgeon general to conclude smoking is a cause.
The report also finds that the risks of lung cancer are far higher today than in past decades, even though smokers today consume fewer cigarettes. In 1959, women who smoked were 2.7 times as likely as women who never smoked to develop lung cancer, and by 2010, the additional risk had jumped nearly tenfold. For men, the risk doubled over the same period. The report said changes in cigarettes’ design, namely to the filter, contributed to the increased deadliness.