CT lung cancer screening saves lives

BROWN (US) — A new study reports a 20 percent reduction in lung cancer deaths in heavy smokers who had low-dose computed tomographic (LDCT) screenings instead of X-rays.

“The results of the study say that the time has come for considering LDCT screening for lung cancer,” says Constantine Gatsonis, professor of medical science at Brown University. “For the first time we have a study that says, ‘Yes, you can actually reduce lung cancer mortality in heavy smokers via screening.’ This is tremendous.”

The National Lung Screening Trial, published online in the New England Journal of Medicine, does not include other significant data about cost-effectiveness, health care utilization, and changes in smoking behavior. That information will be released in the next six months.

The need for further analysis is significant because screening is only one procedure in a much broader health care process, says Ilana Gareen, assistant professor of epidemiology at Brown.

She and Gatsonis noted that LDCT scans have a high false-positive rate that can lead to follow-up screens and biopsies even when there is ultimately no cancer. After three rounds of annual screening with LDCT, for example, 39.1 percent of participants had at least one screen result that was positive for lung cancer. The vast majority of such findings were false alarms.

“The impact of LDCT screening on lung cancer mortality cannot be considered in isolation,” Gareen says. “The screening and subsequent diagnostic work-up will also impact patients’ emotional and physical health and will result in increased levels of health care utilization that may tax an already over-burdened health care system.

To provide information for patients and decision makers, we are studying these downstream consequences.”

Deeper analyses underway

Statistical simulation models will allow researchers to predict the effects of screening in populations beyond the 53,454 people studied in the NLSTl, that focused on people aged 55 to 74 who smoked for at least 30 “pack years” (i.e., a pack a day for 30 years or two packs a day for 15 years).

The models may also be able to provide health officials with guidance on whether people would still benefit if they were screened every other year instead of annually.

In the next six months, data on other aspects of the study will be published: differences in post-screening smoking behavior between patients who received X-ray and helical LDCT scans; differences in utilization of health care between the two groups; and cost-effectiveness of the two procedures.

The authors say in particular the cost-effectiveness analysis is vital to formulating a recommendation for patient care or insurance reimbursement.

“Before crafting public policy recommendations, the cost-effectiveness of helical LDCT screening must be rigorously analyzed,” the authors write. “Against the reduction in lung cancer mortality, the harms from false positive screening results, and over-diagnosis and costs must also be weighed.”

Researchers from Dartmouth College and the National Cancer Institute contributed to the study.

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