The National Cancer Institute (NCI), part of the National Institutes of Health, in partnership with the American Cancer Society, has enrolled its goal of 50,000 current or former smokers in the National Lung Screening Trial (NLST).

The study, launched in September 2002, was designed to determine if screening with either spiral computed tomography (CT) or chest X-ray before the appearance of symptoms can reduce deaths from lung cancer. Although the trial has reached its 50,000 participant goal, it remains open at select sites to collect blood, urine and phlegm to help doctors identify biomarkers, or tumor markers, of lung cancer.

"Reaching this goal is a tremendous first step in our efforts to learn as much as we can about lung cancer screening," said NCI Director Andrew von Eschenbach, M.D. "This is a critically important trial and a rapid accrual means we're moving quickly forward to obtain answers about screening. This is very encouraging."

Spiral CT, a technology introduced in the 1990s, 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 3-dimensional model of the lungs. To date, no scientific evidence has shown that screening or early detection of lung cancer with either spiral CT or chest X-rays actually saves lives.

Regional American Cancer Society offices have helped NLST sites raise awareness of the trial in their communities, while the American College of Radiology Imaging Network (ACRIN) -- a network of researchers who conduct imaging clinical trials, supported by NCI's Division of Cancer Treatment and Diagnosis -- and the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, also funded by NCI, are conducting the trial at more than 30 sites across the country.

"The American Cancer Society is pleased to be part of an ongoing collaboration to encourage enrollment in NLST," said Ralph B. Vance, M.D., national volunteer president of the American Cancer Society. "We are extremely proud of our ability to help contribute to an enrollment rate that is significantly ahead of schedule, although accrual for the trial continues. The Society will continue to support this trial until the results are known. We believe what we learn from NLST will lead to saving more lives from lung cancer."

NLST is a randomized, controlled study, the "gold standard" of research studies. Study participants have been randomly assigned -- designated by chance -- to receive either a chest X-ray or a spiral CT once a year for three years. Researchers will continue to contact participants annually to monitor their health until 2009.

"We commend NLST sites for reaching this goal in 16 short months," said NLST Project Officer John Gohagan, Ph.D., of NCI's Division of Cancer Prevention, "and now it is just as crucial for participants to return for their follow-up X- ray or scan."

"Over the coming years of this trial," predicted ACRIN researcher and NLST Principal Investigator Denise Aberle, M.D., of the University of California Los Angeles, "NLST participants will play a key role in answering critical questions about the use of screening with chest X-ray or CT scans to lower lung cancer deaths."

According to the Centers for Disease Control and Prevention, men who smoke increase their risk of death from lung cancer by more than 22 times; women who smoke increase their risk of death from lung cancer by nearly 12 times. There are an estimated 90 million current and former smokers in the United States.

More people die of lung cancer in the United States than cancers of the breast, prostate, colon, and pancreas combined. This year, the disease will claim an estimated 160,000 lives in this country.