CT screening may detect lung cancer early

By David Douglas

NEW YORK (Reuters Health) - Annual computed tomographic (CT) screening for lung cancer resulted in the identification of a high proportion of patients who had early-stage disease, researchers report in the journal Radiology.

Principal investigator Dr. Claudia I. Henschke told Reuters Health that when CT screening is performed it is important to use an approach that is well-defined and well-tested to identify the patients who need further testing, what testing is needed and when it should be done.

However, this report by Henschke and her colleagues follows a study published in the March 7, 2007 issue of the Journal of the American Medical Association that found no meaningful reduction in deaths from lung cancer due to CT screening. A much larger study of 50,000 people, sponsored by the National Cancer Institute, is now underway that researchers say will be more definitive.

In the current study, Henschke, of New York Presbyterian Hospital-Weill Cornell Medical Center, and colleagues evaluated 6,295 subjects who were an average of 66 years old and had a history of smoking.

The results of the initial CT imaging led to recommendations for further workup in 906 (14.4 percent) subjects and for 361 (6.0 percent) of the 6014 annual repeat screenings.

In total, 101 patients had a diagnosis of lung cancer following the first CT test. Another three participants had a lung cancer diagnosis following symptoms, which developed before the repeat screening was performed. In all, 95 (91.3 percent) of these patients had no evidence that the cancer had spread (metastasized).

In the 20 patients for whom the diagnosis of lung cancer was made following the repeat screening, 17 (85 percent) had no evidence of metastasis.

Of a total of 134 recommended biopsies, 125 (93.3 percent) resulted in the diagnosis of lung cancer or another malignancy.

"These figures are very similar to those with mammography screening and quality assurance of mammography screening has proven highly successful in providing early diagnosis and early treatment for breast cancer," Henschke said.

"We have shown that we can diagnosis lung cancer early -- early treatment of early lung cancer is usually curative," she concluded.

SOURCE: Radiology, April 2007.