Nov 04, 2010 - 3:12 pm
Trial of 53,000 smokers is first to show screening can save lives
By Maggie Fox
WASHINGTON — "Spiral" CT scans cut lung cancer deaths in smokers by 20 percent, researchers reported Thursday in a finding that validates a controversial theory that screening can save lives.
The low-dose scans, a type of X-ray that gives a more complete picture of the lung, apparently catch tumors early, before they have spread, a team sponsored by the U.S. National Cancer Institute found.
The trial of more than 53,000 current and former heavy smokers found the CT scans were better than an ordinary chest X-ray at spotting tumors.
Critics of the scans fear that smokers may not be motivated to quit if they believe screening can save their lives if they do get cancer.
The middle-aged and elderly smokers were scanned with either three spiral CTs a year or one annual chest X-ray starting in August 2002. They were followed for five years.
The researchers said their findings could save thousand of lives. Lung cancer is the No. 1 cancer killer worldwide, killing 1.2 million people a year globally and it will kill 157,000 people in the United States alone this year, according to the American Cancer Society.
Caught early, lung cancer can be cured surgically, but it causes vague symptoms and usually is not diagnosed until it has spread.
In 2006, Dr. Claudia Henschke of New York Presbyterian Hospital-Weill Cornell Medical Center caused a stir when she published a study saying that 80 percent of lung-cancer deaths could be prevented through widespread use of spiral CT.
"This is the first time that we have seen clear evidence of a significant reduction in lung cancer mortality with a screening test in a randomized controlled trial," Dr. Christine Berg of the National Cancer Institute said in a statement.
Almost all advanced CT scanners can perform a spiral CT, and about 60 percent of U.S. hospitals have such a machine. Makers include General Electric Co's GE Healthcare Siemens AG, Toshiba Corp, Hitachi and Philips.
Dr. Denise Aberle, who led the study, said it provided "objective evidence" of the benefits of low-dose scans in older, high-risk people and suggests if it is "implemented responsibly, and individuals with abnormalities are judiciously followed, we have the potential to save thousands of lives."
But Aberle added that with the high association between lung cancer and cigarette smoking, "the single best way to prevent lung cancer deaths is to never start smoking, and if already smoking, to quit permanently."
About 10 percent of smokers develop lung cancer, but smoking causes other cancers as well as heart disease and stroke.