National Lung Screening Trial Delayed

Enrollment in the National Lung ScreeningTrial (NLST), which was projected to have begun this spring, has been delayed.The National Cancer Institute (NCI) apparently wants to ensure that it makesevery effort to listen to the complaints of critics.

An NCI spokeswoman saysthere is no official start date for the trial, which is expected to enroll50,000 people. The NLST is a randomized, controlled trial in which individualsat high risk for lung cancer will be randomly assigned to either low-dose spiralcomputed tomography (CT) or chest x-ray. The study will be large enough todetermine if there is a 20% or greater difference in mortality between the twoscreening modalities.

Much of the criticism of the NLST has come from radiologistClaudia Henschke, MD, a respected crusader for lung cancer CT screening. Shevehemently argued her case, most recently, in April during an appearance beforethe House Ways & Means health subcommittee. Henschke, a radiology professorat Weill Medical College, Cornell University in New York, is the principalinvestigator for the Early Lung Cancer Action Program (NY-ELCAP), a 10-year-oldtrial with a substantially different design than the NLST.

In her appearancebefore the health subcommittee, Henschke argued that a randomized trial wouldtake too long, be too expensive, and would be "unlikely to provide ananswer as it has the same design flaws that recently caused the firestorm aboutmammography screening." She asked members of the subcommittee to force theNCI to change its trial design. other notable opposition to the NLST came whenNCI’s Board of Scientific Advisors voted on the trial on November 14, 2001;the vote was 17-8 in favor with one abstention.

Denise Aberle, MD, professor of thoracic imaging and vice chairof research in the department of radiology at UCLA School of Medicine, andprincipal investigator of the American College of Radiology Imaging Networkcomponent of the NLST, insists that there is no substitute for a large,randomized trial. "Unlike treatment trials, in which survival is anappropriate outcome measure, we cannot look at survival, case-fatality, or othersurrogate end points such as tumor size to determine the benefits ofscreening," she states.