Lung cancer deaths account for about 25% of total cancer deaths—more than any other type of cancer. Cigarettes were responsible for the massive increases in lung cancer deaths throughout the ’60s, ’70s, and ’80s. There’s a lag between when smokers begin using cigarettes and when they develop cancer, but the decades-long decrease in deaths is related to the decrease in smokers over time. In 2017, the American Lung Association noted that only about 14% of adults smoked, compared to over 40% in 1965.

However, smoking isn’t the only cause of lung cancer; some causes are purely genetic. And fortunately, in the last decade, there’s been another big factor improving lung cancer death rates: better drugs to treat it.

Lung cancer has particularly high fatality rates because clinicians often find it only after it has progressed substantially, when it’s harder to treat. That’s why the American Cancer Society recommends that anyone between 55 and 74 who still smokes, or quit smoking within the last 15 years, receive an annual CT scan checking for lung cancer. Thankfully, in the last decade more drugs to treat later-stage forms of the disease have hit the market.

A leader among these are immunotherapies, which modify parts of the body’s immune system to attack the cancer cells. Ned Sharpless, the director of the National Cancer Institute, told the Washington Post that he expects cancer deaths will continue to fall as clinicians learn how to better combine immunotherapies with other treatments, like chemotherapy and radiation.

While lung cancer deaths have fallen, though, clinicians caution that cancer death trends in total may not follow. Instances of cancers linked to higher weight, like uterine, kidney, and pancreatic cancer, are increasing. “What we’re seeing with obesity is really sort of parallel to what we saw with cigarette smoking,” Timothy Rebbeck, an epidemiologist at Harvard and the Dana-Farber Cancer Institute, told the New York Times.

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