Last year, a National Cancer Institute study found that, compared to standard chest X-rays, screening with spiral CT scans reduced lung cancer deaths by 20 percent. Now, based on their own review, the American College of Chest Physicians and the American Society of Clinical Oncology are recommending that high-risk smokers those between the ages of 55 to 74 who have at least a 30 pack-year history of smoking should undergo the annual CT scan, even if they ve quit within the past 15 years.
The recommendation, however, is rather controversial, considering that 19 out of 20 positive results will actually be false positives, warns study co-author Dr. Michael K. Gould, assistant director for health services research at Kaiser Permanente of Southern California, Pasadena.
That s why the study authors insist that CT screening should not be performed in smokers or ex-smokers who do not qualify as high-risk, nor in those who already have a limited life expectancy and are unable to receive treatment.
The review, which was published in the Journal of the American Medical Association, included eight randomized trials and 13 cohort studies, yet the recommendation was largely based on the National Lung Screening Trial. The results of that study found that, after three yearly rounds of CT screenings, three out of every 1,000 high-risk smokers was saved over the course of seven years a number that is comparable to the absolute benefit of mammography screening in older women.
Overall, however, the recommendations were labeled weak under the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system, which led to much debate at JAMA on whether to publish the recommendation at all. Ultimately, though, Dr. Howard Bauchner, the journal s editor in chief, decided to publicize the results: 160,000 U.S. adults die of lung cancer annually, and there s been little progress over the last decade; this is the first hope we have that we can impact those data, he says.
ACSH's Dr. Ruth Kava agrees, and adds that, even though this screening hasn t been studied widely enough, studies such as these allow for the advancement of the technique s evaluation.