More older former smokers need lung cancer screening, experts say

New lung cancer screening guidelines issued by the American Cancer Society (ACS) on Wednesday (Nov 1) call for annual testing with low‐dose computed tomography (CT) for anyone aged 50 to 80 who was formerly a long-term or heavy smoker, a recommendation that could affect millions of Americans.

Previously, the ACS called for screening only for long-time or heavy smokers who had given up cigarettes less than 15 years earlier. The new guidance from the influential organisation says the need for screening should no longer be determined in part by how much time has passed since smokers quit.

The ACS says the new guideline applies to anyone who smoked for 20 so-called pack-years, for example, a pack a day for 20 years or two packs a day for 10 years.

"A lot of times people don't consider themselves a smoker because they haven't smoked in 10, 15 or 20 years," ACS Chief Scientific Officer Dr. William Dahut said at a press conference.

If you have a significant smoking history and quit when you were 28 years old and now you're 55, he said, "you definitely should be screened."

Annual screening would then be appropriate for nearly five million US smokers and former smokers, the ACS said.

The traditional assumption had been that after 15 years of no longer smoking, the risk of lung cancer had dropped to such a low level that screening was no longer cost effective.

New data show that as former smokers' lung cancer risk from smoking goes down, their risk of these malignancies from aging goes up, ACS researchers said at a press conference on Monday.

The lung cancer risk to former smokers does decrease over time when compared with similar people who continue to smoke. When compared with never-smokers, however, their risks remain three times greater even when 20 or 30 years have passed since they quit, the researchers said.

To develop the new guideline, ACS researchers conducted extensive reviews of the medical literature, computer models, and intervention and surveillance data from the US National Cancer Institute.

The update also expands the organisation's recommended age range for lung cancer screening to 50 to 80 years, from the previous range of 55 to 74 years, and decreases the number of required pack-years from 30 to 20.

"Recent studies have shown extending the screening age for persons who smoke and formerly smoked, eliminating the years since quitting requirement and lowering the pack per year recommendation could make a real difference in saving lives," Dr Robert Smith, a senior vice president at the ACS, said in a statement.

While ACS guidelines are highly regarded by the medical community, whether insurance companies will pay for screening in longer-term former smokers is not yet known, the researchers acknowledged.

The US Medicare health plan for Americans age 65 and older generally follows recommendations of the government-backed US Preventive Services Task Force, which still calls for yearly lung cancer screening of former smokers who have quit within the past 15 years, they noted.

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