Annual screening for lung cancer with CT scan can identify lung cancers at an early curable stage, resulting in high 10-year survival rates, according to results of the International Early Lung Cancer Action Program (I-ELCAP).
Previous trials have demonstrated the "spiral" CT results in the early diagnosis of lung cancer among subjects at increased risk, I-ELCAP investigators report in The New England Journal of Medicine. Until now, however, no one had investigated if early intervention affects the outcome of these patients.
The I-ELCAP study included nearly 32,000 men and women with no symptoms but who were considered have a higher than normal risk of developing lung cancer because of a history of smoking, exposure to secondhand smoke, or occupational exposure to asbestos, beryllium, uranium or radon. The subjects were at least 40 years old and underwent CT screening between 1993 and 2005.
A diagnosis of lung cancer was made in 484 subjects: 405 at their first screening, 74 during an annual screening thereafter, and 5 individuals who developed symptoms within a year of the first screening.
A total of 411 subjects underwent surgical removal of their cancer, 57 were treated with radiation or chemotherapy, and 16 received no treatment. The estimated overall 10-year survival rate was 80 percent.
Of the 484 diagnosed patients, 85 percent had clinical stage I lung cancer, the earliest type. For these patients, the estimated 10-year survival rate was 88 percent.
Lead author Dr. Claudia I. Henschke, from the Weill Medical College of Cornell University in New York, and her colleagues note that currently in the US, 95 percent of individuals diagnosed with lung cancer die within 5 years. They suggest that 80 percent of these deaths could be prevented by annual screening CT.
They also maintain that CT screening would be highly cost-effective, similar to the cost-effectiveness for mammography screening.
In an accompanying editorial, Dr. Michael Unger, from Fox Chase Cancer Center in Philadelphia, points out that the US Preventive Services Task Force concluded in 2004 that the evidence was insufficient to make a recommendation either for or against CT screening to detect lung cancer.
Unger explores the lack of progress in evaluating methods to enable early detection of lung cancer. "Unfortunately, he writes, "we have not left behind the idea that lung cancer is a punishment, not a disease" and that the associated stigma has slowed research on early detection.
He adds that the current study "is a provocative, welcome salvo in the long struggle to reduce the tremendous burden of lung cancer on society."