A study out today in the Journal of the American Medical Association (JAMA) finds routine chest X-rays do not reduce the risk of death from lung cancer in smokers or former smokers. The large study involving more than 150,000 older Americans was done by the National Cancer Institute (NCI) and found those who had annual chest X-ray screenings over four years were just as likely to die of lung cancer as study volunteers who did not get screened.
Those who have been following this issue might well ask: didn’t we know that already? We asked Robert A. Smith, PhD, director of cancer screening why the study was done.
“Back in the late 1980’s there was general agreement that the lung cancer screening trials that were done in the 1970’s had serious methodological limitations, principally contamination rates in the control groups that resulted in comparing death rates in two groups each of which had undergone regular lung cancer screening.
“All in all, while the results were null, there were a long list of concerns that led to a lack of confidence in the findings. NCI investigators thought there was a real chance that there was a true benefit of 10-15%, so they included a lung cancer screening arm in the PLCO. Keep in mind that the NCI funded most of the trials in the 1970s. So, the goal here was to try to do a trial that would produce results that would stand up to scrutiny.
“It is true that many people thought the question had been resolved by the old trials, but they really were a bad lot, which is why the NCI was prepared to address the question one more time. I think what we observed in the run up to use of spiral CT was an attempt to cast doubt on the value of lung cancer screening with any technology, which meant dressing up the old trials with new credibility.”
To read more about the promise, and limitations, of lung cancer screening, see: Can Lung Cancer Be Detected Early? on cancer.org.