BETHESDA, MdThe National Cancer Institute has launched a
randomized, 3,000-person study to determine the feasibility of doing
a larger scale trial to test whether spiral CT screening improves
lung cancer survival. Six centers began recruiting volunteers in
early September and hope to enroll 500 subjects each by the end of October.
Researchers will randomly assign participants to receive either a
spiral CT scan or a chest x-ray. One goal of the year-long, $3
million Lung Screening Study (LSS) is to learn whether people at high
risk for lung cancer will enter a trial in which they might not
receive spiral CT.
LSS will also compare the lung cancer detection rate for each of the
two screening tests; determine the kind and the amount of medical
follow-up that is needed for positive or ambiguous results; and track
whether and how often participants get CT scans outside the study.
Subjects must be age 55 to 74 and have a history of long-term or
heavy smoking. Former smokers must have ceased smoking within the
last 10 years.
In a relatively quick time frame, we will learn if smokers are
willing to be randomized to receive something other than spiral
CT, said principal investigator John Gohagan, chief of
NCIs Early Detection Research Group in the Division of Cancer
Prevention. We will also learn about the medical follow-up of
people who have the scanshow extensive and expensive it tends
No screening procedure for lung cancer, including spiral CT scanning,
has been proven to increase survival. Yet despite this fact, many
cancer specialists doubt the willingness of smokers to accept a
screening test other than spiral CT.
Data from the New York-based Early Lung Cancer Action Program
(ELCAP), first reported last year, showed that spiral CT screening of
1,000 smokers and former smokers age 60 and over detected suspicious
lung lesions in 233 participants. Of these, 27 were diagnosed with
lung cancer, 85% of which were stage I tumors. The findings attracted
media coverage and caused a number of radiology centers to offer and
advertise the procedure as a screening test.
Claudia I. Henschke, MD, PhD, who leads ELCAP, and an international
group she helped organize now plan to conduct larger studies of
spiral CT screening in people at high-risk of lung cancer. The
expanded ELCAP trial and the international study will each enroll
10,000 participants. As with the original ELCAP, these are both
NCI said that a randomized study to prove whether spiral CT scanning
can increase survival would be expensive and require tens of
thousands of participants and 5 or more years. Thorough review of
results from the LSS will help researchers decide whether such a
study is feasible.
The LSS is using the scientific structure established for the
150,000-participant Prostate, Lung, Colon, and Ovarian Cancer
Screening Trial (PLCO), which NCI began in 1992. The six centers
involved in LSS are also part of the PLCO study. NCI chose them
because of their experience in recruiting and tracking volunteers in
cancer screening trials.
Board-certified radiologists will review all the results from the LSS
screening exams, and participants and their physicians will be
notified of the results within 3 weeks. Those with positive chest
x-rays will receive a recommendation for standard follow-up care.
Because there is currently no standard follow-up for positive CT
scans, participants with positive scans will be advised to see their
primary care physician and to consult a specialist.
The centers participating in LSS are Georgetown University Medical
Center/Lombardi Cancer Research Center; the Detroit-based Henry Ford
Health System; the University of Minnesota School of Public
Health/Virginia L. Piper Cancer Institute; Washington University
School of Medicine; Marshfield Medical Research and Education
Foundation in Wisconsin; and the University of Alabama at Birmingham.