Current and former smokers are needed for a new study to learn if screening people with either CT scans or chest X-ray before they have symptoms can reduce deaths from lung cancer. The National Lung Screening Trial, or NLST, launched last week by the National Cancer Institute, will enroll 50,000 participants and take place at Hopkins and 29 other sites throughout the United States.
Participants in the randomized, controlled, "gold standard" study will be assigned to get either a chest X-ray or a CT scan once a year for three years. Researchers will continue to contact participants annually until 2009 to monitor their health.
By the time of conventional diagnosis, in 15 percent to 30 percent of cases lung cancers have already spread. Spiral CT, a technology introduced in the 1990s, can pick up tumors well under 1 centimeter in size, while chest X-rays detect tumors about 1 to 2 centimeters in size.
"Conventional wisdom suggests that the smaller the tumor when it is found, the more likely the chance of survival--but that remains to be proven," said Denise Aberle of UCLA, who is co-director of the trial. "Because of the number of individuals participating, and because it is a randomized, controlled trial, NLST will be able to provide the evidence needed to determine whether spiral CT scans are better than chest X-rays at reducing a person's chances of dying from lung cancer."
Elliot Fishman, a professor of radiology at Johns Hopkins, said, "Lung cancer kills more people than cancers of the breast, prostate, colon and pancreas combined, and will claim nearly 155,000 lives this year. Our hope is that this study will lead to saving lives."
According to the NCI, 3,200 people in Maryland will get lung cancer in 2002, and 2,900 will die of it.
To carry out the trial, the National Cancer Institute is using two research networks funded by the institute: the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, and ACRIN, a network of researchers who conduct imaging studies. NCI is collaborating with the American Cancer Society to organize grassroots recruitment efforts at NLST sites.
"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 those of other cancers, have not declined," said trial co-director John Gohagan, of NCI's Division of Cancer Prevention. "Cigarette smoking is by far the most important risk factor in the development of lung cancer."
Spiral CT uses X-rays to scan the entire chest in about 15 to 25 seconds, during a single breath hold. A computer creates images from the scan, assembling them into a three-dimensional model of the lungs. More than half the hospitals in the United States own a spiral CT machine and routinely use it after diagnosis for determining how advanced the cancer is. Recently some hospitals have begun using spiral CT scans to find smaller lung cancers in smokers and former smokers, although no scientific evidence to date has shown that such screening, or even early detection of lung cancer, actually saves lives.
In addition to the lung cancer screenings, some NLST centers will collect blood, urine and sputum. These samples will be used for future research to test for biomarkers that may someday help doctors better diagnose lung cancer.
Participants in NLST will receive lung cancer screenings free of charge. Men and women can participate in NLST if they are 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), are not currently 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.
Additionally, participants interested in quitting smoking can receive referrals to smoking cessation programs.
For more information about the trial, go to cancer.gov/NLST.