CT Scans for Smokers Could Lower Lung Cancer Deaths by 20 Percent
June 29, 2011— -- Phyllis Curtis of Baltimore said she might not be alive today if she hadn't heard an advertisement on the radio calling for heavy smokers to volunteer to test out lung cancer screening using CT scans.
Though Curtis, now 67, ended her 24-year, pack-a-day habit when she was 40 years old, her initial scan, which was done at Johns Hopkins as part of the National Lung Screening Trial, revealed a lump in her right lung that turned out to be cancer.
"I didn't have any symptoms -- no coughing, no raspy voice. I didn't have any indication, so I never would have thought to get screened," says Curtis.
Curtis is an example of why CT screening may prove to be a game-changer, says Dr. William Black, who headed the Dartmouth Medical School branch of the NLST, a seven-year study on the effectiveness of CT scans in scoping out lung cancer.
If all current or former heavy smokers over 55 were screened like Curtis was, there could be as much as a 20 percent reduction in the number of people dying from lung cancer, according to the results of the NLST, published in full today in the New England Journal of Medicine.
These study results, first hinted at in a preliminary report released last November, offer the first solid evidence that screening high-risk patients using CT scans could reduce lung cancer deaths -- a finding that has at least 20 of the nation's major medical centers setting up CT lung screening programs of their own.
Right now, a lung cancer diagnosis is in many cases a death sentence, because the majority of these cancers are caught late, when there is only a 15 percent chance of surviving five years, says Dr. Philip Linden, chief of the Division of Thoracic and Esophageal Surgery at University Hospitals Case Medical Center in Cleveland.
If caught earlier, 60 percent to 90 percent of lung cancers are curable, he says, making "a tool to diagnose lung cancer earlier ... a tremendous opportunity."
Past studies have found that screening for lung cancer with a standard chest X-ray offers little to no benefit in preventing deaths from the disease. When researchers compared screening once a year for three years using CT scans with the same screening protocol using chest X-rays, they found that CT scans, which are more sensitive, led to significantly fewer lung cancer deaths.
There are no official recommendations or guidelines for lung cancer screening, and the NLST authors say it's too early in the research to make such recommendations, but many hospitals have moved ahead with screening programs anyway, saying the potential to save lives is too great to wait any longer.
Currently, hospitals screen only those at particularly high risk: older patients who have at least 30 "pack years" under their belts, meaning they smoked a pack a day for thirty years, or the equivalent.
William Kennedy, 57, is one such candidate: He smoked as many as four packs a day in the 37 years he was a smoker. His father, also a smoker, died at 68 from lung cancer, so Kennedy jumped at the chance to get screened Tuesday at University Hospitals Case Medical Center in Cleveland,
"Knowledge is power. Good, bad, or indifferent, the sooner I know the results, the better," he said.
Lung Screening for the Nation?
As with most types of cancer screenings, the potential to catch and cure more lung cancers is weighed against the cost of widespread and regular screening, as well as the psychological burden of false positives that more screening often produces.
In the NLST study, about 27 percent of those screened had a false positive: Their first CT scan showed a suspicious, potentially cancerous, nodule in their lungs that upon further scans or a biopsy turned out to be benign, explains Dr. William Black, who headed the Dartmouth Medical School branch of the NLST.
Among those with an initial positive scan, 96.4 percent ended up not having cancer upon further testing.
