Conventional wisdom suggests that finding tumors earlier, when they are smaller and less likely to have spread outside the lung, increases cancer survival rates. Many health professionals therefore hypothesize that spiral CT scans are superior to chest x-rays, because spiral CT can pick up tumors well under 1 centimeter in size, while chest X-rays can detect only larger tumors, about 1 to 2 centimeters in size. However, no scientific evidence to date has shown that early detection of lung cancer, or screening by either method, actually saves lives. Moreover, screening may detect abnormalities that lead to unnecessary diagnostic tests and procedures to remove noncancerous lesions.
The trial is a randomized, controlled study--the gold standard of research studies. Study participants will be randomly assigned to receive either a chest X-ray or a spiral CT once a year for three years, and their health will be monitored annually until 2009. Researchers believe that because of the study's size and the fact that participants will be randomized, NLST will be able to provide the evidence needed to determine which test is better at reducing deaths from lung cancer.
Spiral CT uses x-rays to scan the entire chest in about 15 to 25 seconds, during a single breath hold. Throughout the procedure, the participant lies still on a table. The table and patient pass through the CT scanner, which is shaped like a donut with a large hole. The scanner rotates around the participant and a computer creates images from the scan, assembling them into a 3-D model of the lungs.
More than half of U.S. hospitals own a spiral CT machine and routinely use them to determine how advanced a patient's cancer is after diagnosis. Some hospitals have recently begun performing spiral CT scans as a way of finding early lung cancer in smokers and former smokers--despite the lack of scientific evidence that this actually saves lives.
"Lung cancer kills more people than cancers of the breast, prostate, colon, and pancreas combined, and it will claim nearly 155,000 lives this year--300 of them in the District of Columbia alone," said Edward P. Gelmann, MD, professor of medicine and oncology and the principal investigator of NLST at Lombardi. "Our hope is that this study will lead to saving lives."
"NLST is important because there are more than 90 million current and former smokers in the United States at high risk for lung cancer, and death rates for this disease, unlike many other cancers, have not declined," said NLST co-director John Gohagan, Ph.D., of NCI's Division of Cancer Prevention.
Participants in NLST will receive lung cancer screenings free of charge. To qualify, participants must be current or former smokers ages 55 to 74; have never had lung cancer and have not had any cancer within the last five years (except some skin cancers or in situ cancers); not currently be enrolled in any other cancer screening or cancer prevention trial; and have not had a CT scan of the chest or lungs within the last 18 months. Participants who would like to quit smoking can receive referrals to smoking cessation programs.
To find out more about the NLST study at Lombardi, or to arrange an interview with Dr. Gelmann, members of the media may call Beth Porter at (202) 687-4699.
For additional information about NLST:
• Call the National Cancer Institute's Cancer Information Service toll-free, Monday through Friday, 9 a.m. to 4:30 p.m., at 1-800-4-CANCER (1-800-422-6237) for information in English or Spanish.
• Log on to cancer.gov/NLST.
The Lombardi Cancer Center, part of Georgetown University Medical Center, is a full-service cancer center that includes a strong core of basic science and clinical research, a program of high-priority clinical trials, and a commitment to community service and outreach activities related to cancer prevention and control. Lombardi is one of only 39 National Cancer Institute-designated comprehensive cancer centers in the nation, and the only one in the Washington DC area.