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Study Confirms CT Scans Reduce Lung Cancer Deaths

Article date: June 30, 2011

By Stacy Simon

Detailed analysis confirms earlier findings that a kind of low-dose CT scan to screen for lung cancer in heavy smokers reduced deaths from lung cancer by 20% over simple chest x-rays. The report of the National Lung Screening Trial (NLST) was published online Wednesday in the New England Journal of Medicine. Early findings of the study were made public in November 2010.


The NLST included more than 53,000 current or former heavy smokers aged 55 to 74. Participants had no history or signs of lung cancer, and all had a smoking history equivalent to smoking at least a pack a day for 30 years. Participants were randomly selected to be screened once a year for 3 years with either the low-dose helical CT scan or standard chest x-ray. After an average of about 6 years, those getting CT scans were 20% less likely to die of lung cancer than those getting chest x-rays.

However, the low-dose CT scans also found a lot more suspicious areas that turned out not to be cancer. Nearly 1 out of 4 people getting CT scans, as opposed to only about 7% of people getting chest x-rays, had an abnormal finding that turned out not to be cancer, but they required further testing to be sure. In most cases this testing was more CT scans, but some people got more invasive procedures, which in rare cases caused serious problems.

More analysis of the data from the NLST is now under way. Researchers are looking at the cost-effectiveness of the CT scans, and trying to determine how often and for how long people should be screened. Researchers also hope to develop models that may help indicate whether other groups of smokers, such as light smokers or younger smokers, would benefit from CT screening.

Otis W. Brawley, MD, chief medical officer of the American Cancer Society, says, "This is a momentous time in the history of public health research, and the NCI investigators are to be congratulated. The NLST study is the best designed and best performed lung cancer screening study in history. These are very important findings, and they will be considered as major groups including the American Cancer Society create recommendations for the early detection of lung cancer."

Lung cancer is by far the leading cause of cancer death among both men and women. And smoking accounts for 87% of lung cancer deaths.

Dr. Brawley cautions that not smoking is still the best defense against lung cancer: "While the study showed that screening can reduce the risk of lung cancer death in current and former smokers, we must always emphasize that screening is a secondary risk reduction strategy to smoking cessation. Proven smoking cessation strategies and the policies that promote them, including strong smoke-free laws, higher tobacco taxes, and fully funded smoking cessation programs, remain critical in the fight against cancer. The findings of this study do not diminish their importance, nor do they suggest that resources could be shifted from prevention to early detection. We estimate that quitting smoking will in 10 years’ time reduce a smoker's risk of death from lung cancer as much as CT screening did in this study."

Read more about the NLST in our news article CT Scans Cut Lung Cancer Deaths, Study Finds. For help with quitting smoking, see our Guide to Quitting Smoking and the other resources at cancer.org/quitsmoking.

Reviewed by: Members of the ACS Medical Content Staff

ACS News Center stories are provided as a source of cancer-related news and are not intended to be used as press releases.

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