How do patients respond to lung cancer screening false positives? | CHEST 2026

Lung cancer screening with low-dose CT scans is effective at reducing lung cancer death, with evidence of a 20% reduction in lung cancer mortality among people at high risk of getting lung cancer, usually stemming from a smoking history. But lung cancer screening has been dogged by a high false-positive rate. How high has varied from study to study, depending on whether it was the patient’s first, baseline scan or those done in subsequent years. A 2021 summary of lung cancer screening published by the United States Preventive Services Task Force said the false-positive rate ranged 7.9% to 43% for the baseline screening scan. Guideline writers have worked to limit the problem by adjusting the criteria for what is considered positive on the scan while not missing true cancers, but it hasn’t gone away entirely. Clinicians, advocacy organizations and others concerned with screening have worried that false-positive rates are among the reasons lung cancer screening is underutilized. Research being presented at the 2026 CHEST meeting in Phoenix that is starting today suggests that less than 20% of adults eligible for lung cancer screening are screened, which is far below the approximately 75% uptake of breast cancer screening and the approximately 60% uptake of colorectal cancer.

Findings from two research projects that looked at the false-positive problem from very different perspectives are being presented at the 2026 CHEST meeting in Phoenix that started yesterday and runs through Oct. 21. One examined whether false positives affected patients coming back for the addition, and the other looked at communication about false positives in the context of shared decision-making.

Christina Hsiao, M.D., a resident physician at the University of Washington, and her colleagues found that patients with resolved false positives were more likely to come back for screening than those for whom the scans were negative.

Louise M. Henderson, Ph.D., and her colleagues found through 50 interviews of patients who had experienced false positives that the patients wished that several topics had been discussed with them, including what it means to have nodules in the lungs and the associated additional testing. The abstract includes several patient quotes, including “[Clinicians] really didn’t say there was any risk to screening” and “Just being told you could have a false alarm would be nice. I don’t remember anyone ever saying you could get a false alarm.”

More concerning false positives are associated with a return to screening

Hsiao conducted their retrospective cohort study by using records of patients who had a low-dose CT scan at a multisite lung cancer screening program in Seattle. The American College of Radiology’s Lung CT Screening and Reporting Data System (Lung-RADS) is the standardized way of categorizing lung cancer screening results that takes into account the size of nodules and other characteristics. The researchers classified those with Lung-RADS 3, 4A, 4B or 4X with clinical stability or resolution within 12 months as false positives. Negative scans were those rated as Lung-RADS 1 to 2. The “return to screening” outcome was a screening within 5 months to 15 months after the negative scan or after the initial positive finding of Lung-RADS 3 to 4 had been resolved.

The researchers ended up with 150 patients with resolved false positive findings and 2,854 with negative findings. The number included in their analysis dropped to 2,495 when sufficient follow-up was factored in. In that group, they found just over half (52%) of those with false positives returned to screening, while under half (43%) of those with negative scans did. There was less of a difference when they made some adjustments for covariates. Another slice of the data showed that the difference with those with negative scans was largest among patients whose initial scans were the most concerning (Lung-RADS category 4B or 4X).

Hsiao and her colleagues say that one of the implications of their study is that “highly suspicious” false positives may lead to “ongoing lung cancer concern among patients, driving future screening behavior.” To put it more colloquially, a lung cancer screening false alarm that was suggestive of a serious cancer may make people more, not less, likely to get screened in the future.

‘What are you gonna do?’

The research conducted by Henderson and her colleagues was qualitative, so it did not yield statistical outcomes. In the abstract, they report that their interviews produced five key recommendations about topics that they wished had been explained to them: the lung cancer screening process, their risk for lung cancer and the patient costs; what it means to have nodules and associated testing and its costs; false positives; incorporating patient preferences into decision-making; and a preference for verbal communication about positive findings.

Other quotes that Henderson and her colleagues included one that showed an accepting attitude toward false positives: “I’d still want to know. I’d probably be upset about a bad call, but what are you gonna do? I would still do it again.”