A new generation of CT scanners that can detect cancer in the lungs as small as a grain of rice - when the tumor is still highly curable - is raising hopes that screening may drastically reverse the grim outlook for lung cancer just as mammography did for breast cancer.
A large, long-term study reported in yesterday's issue of the New England Journal of Medicine estimated that at least 88 percent of patients whose early-stage lung cancer was detected through CT screening would survive for 10 years after the tumor was surgically removed.
The 10-year survival rate for people diagnosed with early lung cancer is usually about 70 percent. But 85 percent of tumors are not detected until they are more advanced and difficult to treat.
Many experts lauded the findings and said doctors would now look more closely at using CT scans on patients at risk for the nation's top cancer killer. The scans are currently used to diagnose cancer once symptoms appear, not for routine screening.
But they also cautioned that the results of even larger studies now under way are needed before CT scanning is broadly recommended for people at risk.
Among the concerns about the new study is that because all participants were screened, the findings do not definitively show that scanning reduces the death rate from lung cancer when compared with a similar group of people not screened. CT screening also picks up small lesions, such as tiny scars, that may be confused with cancer, putting a person through additional testing and anxiety.
Nevertheless, experts agreed that the results of the International Early Lung Cancer Action Project are encouraging and cause for hope.
The study, headed by Dr. Claudia Henschke of the New York-Presbyterian Hospital/Weill Cornell Medical Center, followed 31,567 people at risk of developing the disease as they were screened yearly between 1993 and 2005. They were 40 or older and considered at risk for lung cancer because of a history of smoking, occupational exposure to asbestos, beryllium, uranium or radon, or exposure to secondhand smoke.
The screening turned up 484 lung cancer cases, 412 of which were Stage 1 cancer - when it has not spread and can be cured by surgery. These patients' estimated 10-year survival rate after surgery was 88 percent. Of the 302 patients who had surgery within a month after diagnosis, the rate rose to 92 percent.
Eight patients were diagnosed with Stage 1 lung cancer but refused treatment for personal reasons. All died within five years.
"Lung cancer is a very fatal disease," said Dr. David Yankelevitz, a member of the study group, and professor of radiology and cardiothoracic surgery at Weill Cornell Medical College. "Once a person has symptoms [such as coughing, chest pain, shortness of breath, hoarseness, spitting up blood] the chances are enormously high that it's in an advanced stage and the chance for cure is less than 5 percent."
"This study turns it all around," he said. "This basically takes it from being a highly fatal cancer to one that if you're in a screening program and it's caught early, your chances of really being cured are very high."
Ronald Kotulak writes for the Chicago Tribune.