Enrollment in the National Lung Screening Trial (NLST), which was projected to have begun this spring, has been delayed. The National Cancer Institute (NCI) apparently wants to ensure that it makes every effort to listen to the complaints of critics.
An NCI spokeswoman says there is no official start date for the trial, which is expected to enroll 50,000 people. The NLST is a randomized, controlled trial in which individuals at high risk for lung cancer will be randomly assigned to either low-dose spiral computed tomography (CT) or chest x-ray. The study will be large enough to determine if there is a 20% or greater difference in mortality between the two screening modalities.
Much of the criticism of the NLST has come from radiologist Claudia Henschke, MD, a respected crusader for lung cancer CT screening. She vehemently argued her case, most recently, in April during an appearance before the House Ways & Means health subcommittee. Henschke, a radiology professor at Weill Medical College, Cornell University in New York, is the principal investigator for the Early Lung Cancer Action Program (NY-ELCAP), a 10-year-old trial with a substantially different design than the NLST.
In her appearance before the health subcommittee, Henschke argued that a randomized trial would take too long, be too expensive, and would be "unlikely to provide an answer as it has the same design flaws that recently caused the firestorm about mammography screening." She asked members of the subcommittee to force the NCI to change its trial design. other notable opposition to the NLST came when NCI’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 chair of research in the department of radiology at UCLA School of Medicine, and principal investigator of the American College of Radiology Imaging Network component of the NLST, insists that there is no substitute for a large, randomized trial. "Unlike treatment trials, in which survival is an appropriate outcome measure, we cannot look at survival, case-fatality, or other surrogate end points such as tumor size to determine the benefits of screening," she states.