Landmark Study Looks at Impact of Screening on Lung Cancer Outcomes
March 1, 2012
The results showed that screening current or former heavy smokers
with a computed tomography (CT) scan can reduce deaths from lung cancers by 20 percent compared to screening with chest X-ray. Georgetown Lombardi Comprehensive Cancer Center was one of 33 centers around the country that participated in the study, and the only site in the Washington, DC area.
The National Lung Screening Trial, or NLST, involved more than 53,000 current and former heavy smokers ages 55 to 74. Under Georgetown Lombardi’s leadership, 1,800 men and women were recruited into the clinical trial at Georgetown Lombardi as well as two other MedStar Georgetown University Hospital community-screening locations.
The study compared the effects of two screening procedures for lung cancer: lowdose helical computed tomography (CT) and standard chest X-ray. It also examined complications from follow-up procedures after a positive result. The eight-year-long study, the results of which were published
in the New England Journal of Medicine, determined that the CT screening does carry risk, though not common.
“These results are significant. It is clear from this study that CT screening of
smokers or former smokers at high risk of developing lung cancer can save lives,” says Claudine Isaacs, MD, lead investigator of Lombardi n winter 2012 13 the NLST study at Georgetown Lombardi. “That said, with the newly published results, we’re getting a look at the false positive
rate and the complications that can come with follow-up procedures to
positives scans. This is important information when weighing the risks and benefits of screening.”
False-positive results describe scans that show a lesion or artifact in the lung
that, after a follow-up CT scan or invasive procedure (such as a biopsy), are determined to not be lung cancer.
“We are grateful to all the men and women who participated in this important
study. Clinical trials are critical to making progress in medicine,” Isaacs says.
“Going forward, we need to determine who best benefits from this screening and ensure that we are offering those at risk the best course of screening,” says Louis M. Weiner, MD, director of Georgetown Lombardi. “While studies like these generate excitement, clearly there is much more
work to be done. Georgetown Lombardi and our MedStar partner hospitals continue to explore effective ways to reduce lung cancer deaths, including prevention and screening efforts, and conducting clinical trials with the newest diagnostic tools and available cancer fighting drugs.”
Isaacs’s stresses that the best way to reduce the risk of dying from lung cancer was to never start or to quit smoking.
A grateful study participant
Patricia Stewart, a participant in the trial from Alexandria, Va., can attest to that. Her first screening as part of NLST turned out to be positive. She received a CT scan and, after the positive finding, Stewart went to her own physician who thought the spot on the image came from a cracked rib. But
for some in the study, a positive diagnosis led to additional screening and, in some cases, a biopsy before determining the nodule was benign.
Stewart’s second and third scans were negative. She is grateful for the study. She is 74, and with the exception of seven years when she was pregnant and then a mother of a young child, she has been smoking since she was 16. “We were all attracted to the Marlboro Man when I was in school, and I smoked as more of a social thing,” she says.
She says she has cut down her use of cigarettes substantially at times, but stress seems to push her back into the habit. But the NLST study has impressed her, and she wishes that friends of hers who have recently died of lung cancer had been enrolled. “It’s fantastic that the researchers
have determined that scanning can identify a potentially fatal cancer, but I know that the best answer is to quit smoking.”
A closer look at the NLST
The NLST study began enrolling participants in August 2002. Participants were required to have a smoking history of at least 30 pack-years and were either current or former smokers without signs, symptoms or history of lung cancer. Pack-years are calculated by multiplying the average number of packs of cigarettes smoked per day by the number of years a person has
The men and women were randomly assigned to receive three annual screens
with either low-dose helical CT (often referred to as spiral CT) or standard chest X-ray. Previous efforts to demonstrate that standard chest X-ray examinations can reduce lung cancer mortality have been
The trial participants received their screening tests at the time of enrollment
and at the end of their first and second years on the trial. The participants were then followed for up to another five years.
A labor-intensive endeavor
Working behind the scenes as Stewart and the hundreds of other participants enrolled in NLST was a team of radiologists supervised by Matthew Freedman, MD, MBA. Freedman himself played key roles in the
study even before it started and while it was ongoing. He worked to have the study approved by GUMC and MedStar, and he was one of four radiologists who interpreted the images.
“I have been working in the issue of lung cancer since 1968, and in this study it was very interesting to actually be designing the minutiae,” Freedman says. “The data from the study will be a treasure chest for years to come and will help us answer some very interesting clinical questions.”