An xray shows the lungs of a cigarette smoker. Photograph: American Cancer Society via Getty Images
The study of 154,901 participants -- smokers, former smokers and people who never smoked -- found similar rates of death from lung cancer between those who received annual chest X-rays for up to four years and those who got their usual medical care. The research, which followed the patients for 13 years, was released today by the Journal of the American Medical Association.
The findings provide definitive evidence that chest X-rays aren’t a useful tool for finding lung cancer early enough, researchers said. A U.S study last year showed that current and former smokers who received computerized tomography, or CT, scans were 20 percent less likely to die of lung cancer than those who got chest X-rays.
“This study shows us we can’t really expect much at all with lung cancer screening with chest X-ray,” said Robert Smith, senior director for cancer control with the American Cancer Society in Atlanta, who wasn’t an author of today’s paper, in an Oct. 25 telephone interview. “We have already put to rest whether or not lung cancer screening with chest X-ray offers similar benefits to CT screening. It doesn’t. We need to have a better understanding of how to screen for lung cancer.”
Today’s study, called the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, began nine years before the National Lung Screening Trial, which compared CT scans to chest X-rays in current and former smokers. At the start of the trial, chest X-rays were the standard technology used to screen for lung cancer. The results were presented today at the meeting of the American College of Chest Physicians in Honolulu.
CT Scan Sensitivity
CT scans provide a more detailed picture of the lungs than chest X-rays so they are better able to identify small tumors, said study author Christine Berg, chief of the Early Detection Research Group at the National Cancer Institute’s Division of Cancer Prevention in Rockville, Maryland. Researchers didn’t expect to see a benefit from X-rays, though they waited for the data because the study was the definitive trial on the use of chest X-rays as a lung cancer screening tool.
“The problem was it wasn’t finding lung cancer at a small enough size,” she said. “Lung cancer is a very aggressive disease so you have to find it very small in order to cut it out and cure it.”
Future X-Ray Role
In the future, X-rays may play a role in lung cancer screening if the technology improves enough to detect smaller tumors. CT scans can be problematic because they can identify many suspicious nodules that aren’t positive, Berg said. They’re also more costly. Medicare, the U.S. health program for the elderly and disabled, pays about $350 to $370 for a CT scan Institutions generally $750 to $1,000 for the scan while most insurers pay $50 to $100 for an X-ray, she said.
This year more than 220,000 people will be diagnosed with lung cancer and almost 157,000 will die from the disease, which kills more people than any other cancers, according to the National Cancer Institute.
Neither the U.S. Preventive Services Task Force, an independent panel of experts in medicine, nor the American Cancer Society recommend screening for lung cancer. Berg said recommendations for the U.S. task force may be available by the end of 2012.
Lung Association Recommendations
The American Lung Association will have recommendations on lung cancer screening in about three months, said Norman Edelman, the Washington-based group’s chief medical officer, in an Oct. 25 telephone interview.
“Lung cancer kills more people than any other cancer. It’s a devastating disease. The cure rates are small,” he said. “We certainly need better tools to deal with lung cancer. There is a hope that catching lung cancer early will increase survivability. We need a lot more research.”
Researchers in today’s study included more than 154,000 people ages 55 to 74 who were current or former smokers or who never smoked. About half were assigned to annual lung cancer screenings for four years using X-rays and the other half were assigned to receive standard medical care, which included advice on quitting smoking, from 1993 to 2001. They were followed for either 13 years or through December 2009.
During the study period, 1,696 people in the screening group and 1,620 in the standard medical care group were diagnosed with cancer. Chest X-rays picked up 307 cancers, while the rest were found between X-rays or after the screenings ended, Berg said.
Lung-cancer death rates between the groups were similar with 1,213 lung cancer deaths in the X-ray group and 1,230 in the standard medical care group, the research showed.
“Chest X-ray screening would not be recommended for a lung cancer screening program,” said Berg. “I do believe this study doesn’t show any benefit.”
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