Using Low-Dose CT to Reduce Deaths from Lung Cancer
The International Association for the Study of Lung Cancer announces guidelines for global lung cancer screening programs.
Lung cancer is both the most common cancer worldwide and the leading cause of cancer-related deaths, according to the World Health Organization. One major hurdle to improving lung cancer survival rates is that the cancer is often diagnosed after it has spread, leading to worse outcomes for patients. To address this challenge, the International Association for the Study of Lung Cancer (IASLC) recently issued a statement on lung cancer screening with low-dose CT based on results from two large, well-designed randomized trials, which showed that this early-detection approach can significantly reduce deaths from lung cancer in high-risk populations.
One of these studies, known as the NELSON trial, was presented at the IASLC 19th World Conference on Lung Cancer held in late September in Toronto, Canada. Results from the other study, called the National Lung Screening Trial (NLST), were published in 2011 in the New England Journal of Medicine.
“The NELSON screening outcome results not only exceed those reported with the NLST, but also involved younger subjects who were exposed to lower levels of tobacco consumption,” said James Mulshine, chair of the IASLC Early Detection and Screening Committee. “All of these findings reflect growing evidence supporting the significant value of the lung cancer screening service in reducing deaths due to lung cancer.”
The IASLC statement, issued Oct. 25, supports the implementation of global lung cancer screening programs that identify high-risk individuals, consistently acquire high-quality low-dose CT images, and routinely integrate smoking cessation to optimize health outcomes. “The IASLC is working to educate medical professionals on best practices for implementing lung cancer screening across a wide array of clinical settings,” Mulshine said. “In addition, it is supporting the development of a thoracic CT image archive to enable research and education about further improving early lung cancer imaging and management.”
The statement is a step in the right direction, according to Chyke Doubeni, a clinical epidemiologist and health services researcher who studies the comparative effectiveness of screening tests at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. But substantial work needs to be done to optimize the benefits and minimize the harms of screening, he added. “This includes streamlining the approaches for identifying those eligible and ensuring equity in the delivery of lung cancer preventive intervention,” Doubeni said. “One important step is to create benchmarks to guide implementation of lung cancer screening.”
Denise Aberle, the NLST principal investigator and a professor of radiology and bioengineering at the University of California, Los Angeles, agreed that the IASLC recommendations are appropriate and necessary components of lung cancer screening. But she pointed out several challenges, including educating clinicians, refining the list of nodule characteristics that should factor into definitions of a positive screen, and optimizing screening eligibility. “Additional risk variables must be consistently obtained and available in electronic medical records if we hope to improve on screening cohort identification,” she said.
Putting together multidisciplinary teams of radiologists, pulmonologists, surgeons, oncologists and radiotherapists to manage these patients will also be imperative, Aberle noted. “This is most critically a concern in disadvantaged populations, for whom quality medical resources must be made available to act on suspicious lung nodules,” she said. “Ultimately, screening is the essential but initial step in an informed strategy to expeditiously manage patients and reduce lung cancer mortality.”
According to Aberle, implementation of the new health policy may require several years or even decades. “The challenge posed by the IASLC to provide lung cancer screening on a global scale will be formidable, but currently provides the greatest opportunity to curb mortality from lung cancer,” she said. “That alone makes their recommendations both a roadmap and the goal.”