The American Lung Association has thrown its weight behind low-dose CT screening of heavy smokers who meet criteria set forth in the National Lung Screening Trial.
The group emphasized that it does not recommend universal screening at this time, and that it believes chest x-rays should not be used for lung cancer screening. It only recommends low-dose computed axial tomography screening – and only for current or past smokers aged 55-74 years, who have smoked at least 30 pack-years and have no history of lung cancer.
"For those who chose to undergo the screening process, smoking cessation should be continuously emphasized as it remains the best method of reducing lung cancer risk," according to an interim report outlining the new guidance.
The document comes from a seven-member Lung Cancer Screening Committee formed to assess the American Lung Association (ALA)’s position in light of the National Lung Screening Trial (NLST) results – the study was the first to show a screening program could reduce lung cancer deaths. The panel’s charge was to review current evidence about lung cancer screening that would, "offer the best possible guidance to the public and those suffering from lung disease."
The NLST randomized subjects at risk of lung cancer to three annual screenings with either low-dose CT or single-view posteroanterior chest x-rays. Investigators reported that low-dose CT was associated with a 20% decrease in mortality compared with chest x-rays. The false positive rate was 96%, however (N. Engl. J. Med. 2011;365:395-409).
Since the results were announced, the National Comprehensive Cancer Network (NCCN) has similarly endorsed screening of high-risk smokers, and the International Association for the Study of Lung Cancer (IASLC) has urged physicians to discuss screening with patients who smoke. Many other groups have yet to take a stand, however.
Although the landmark trial found solid evidence supporting annual screens in the population studied, the ALA noted it also raised many "personal and public health issues": among them, what to do about false positive results, the physical and emotional risks of screening and any resultant invasive procedures, cost implications, and equitable access to the CT procedure. The ALA task force sought to provide some guidance around these questions.
"Our hope is that this report will serve ALA well in its mission to guide the public on this very important personal and public health issue," noted committee chair Dr. Jonathan M Samet, professor and Flora L. Thornton Chair, of the department of preventive medicine at the University of Southern California, Los Angeles, and coauthors.
"We believe that the report and the educational materials that stem from it will be invaluable to the tens of millions of people at risk for lung cancer."
Also among the key points in the interim report are:
• Providers should continue to stress that smoking cessation is the most important way to reduce the risk of lung cancer.
• ALA should produce a patient-focused toolkit that discusses the risks and benefits of screening, including the physical risks of any invasive diagnostic procedure, and the costs – both financial and emotional – of any false-positive result. The toolkit should have information to help patients with chronic lung disease and their health providers to have a detailed discussion about the risks of any subsequent invasive testing.
• Since low-dose CT screening is not currently covered by Medicare or private insurance, it should not be used to recruit patients. Doing so would focus care on financially advantaged patients over financially disadvantaged. Hospitals and screening centers should ethically promote the procedure with full disclosure of the risks, costs, and benefits.
• ALA should "strongly advocate" for screening to be linked to "best practice" multidisciplinary clinical teams that can provide complete follow-up for any positive finding.
The group has also created separate "FAQ" sheets for patients and for physicians to help them discuss screening in an objective, accurate manner.
Dr. Samet said he has no relevant conflicts of interest.