When actor Dustin Diamond—aka "Screech"—died of lung cancer this week, it illustrated something showing up more and more in cancer stats: The 44-year-old had never smoked, reports Health.com. As a deep dive into the issue by Sharon Begley at STAT News makes clear, smoking is still far and away the leading cause of lung cancer, with a December study finding 84% of women and 90% of men who receive a new diagnosis can be classified as current or former smokers. But also clear is that the proportion of non-smokers being diagnosed is on the rise. For example, a 2017 study in US hospitals found that the percentage of lung cancer patients who were "never-smokers" rose from 8% in 1990 to 1995 to nearly 15% in 2011 to 2013. The researchers' take: "the actual incidence of lung cancer in never-smokers is increasing." A separate study in the UK found an even greater increase, from 13% to 28% from 2008 to 2014.
"If lung cancer in never-smokers were a separate entity, it would be in the top 10 cancers in the US," surgeon Andrew Kaufman of Mount Sinai Hospital tells STAT. He calls it "an epidemiological shift" that's been underway since the 2000s. One factor is that fewer people are smoking these days, meaning that never-smokers will take up more of the statistical pie, explains an epidemiologist with the American Cancer Society. His stance is that a never-smoker does not have a greater chance of getting lung cancer today than in the past. Indeed, scientists are split, with one oncologist saying the issue is made murkier by the fact that most old lung-cancer records don't include smoking status. Still, there's a growing push to learn more about the phenomenon, and even to declare it a disease of its own and treat it accordingly with tailored drugs. One important part of the puzzle: Female never-smokers are twice as likely to get lung cancer as their male counterparts. (Rush Limbaugh, long a cigar smoker, is battling the disease.)