The updated guidelines on lung cancer screening released by the American Cancer Society (ACS) conclude that there is sufficient evidence for screening with low-dose computed tomography (LDCT) in certain high-risk individuals.
The guidelines were published online January 11 in CA: A Cancer Journal for Clinicians. They are an update of interim guidelines issued in 2010, and are based on a systematic review published last year (JAMA. 2012; 307:2418-2429).
The ACS supports screening for lung cancer for people 55 to 74 years with a history of smoking (at least a 30-pack-year history), in those who currently smoke, and in those who quit smoking in the previous 15 years. The ACS also supports an individual's decision not to be screened, even if they fall in this high-risk category.
The LCDT screen is performed annually, and the ACS emphasizes that people should be encouraged to join an organized screening program with expertise in lung cancer and multidisciplinary teams "wherever possible."
"The adoption of lung cancer screening could save many lives," Richard Wender, MD, from Thomas Jefferson University Medical College in Philadelphia, Pennsylvania, and colleagues state in the guidelines, citing evidence from the National Lung Cancer Screening Trial (NLST).
"At this time, there is sufficient evidence to support screening provided that the patient has undergone a thorough discussion of the benefits, limitations, and risks, and can be screened in a setting with experience in lung cancer screening," they add.
The National Comprehensive Cancer Network was the first to recommend annual screening with LCDT for certain populations (in 2011); the American Lung Association followed in 2012.
The American College of Radiology has announced that it is preparing its own set of guidelines to ensure that CT lung cancer screening is performed using "proper personnel, equipment, protocols, and follow-up."
Issues of Concern
Despite the official guidelines and enthusiasm from some medical centers, there has been reticencefrom some lung cancer experts, who are concerned that many details need to be resolved before national screening programs are implemented.
The ACS acknowledges some of these concerns in its guidelines, and notes that high-quality lung cancer screening in the United States "poses many challenges." Whether or not the benefit from screening observed in the NLST will be seen in community-based screening for lung cancer "could be influenced by many factors, and the answer awaits the results of further observations and research," Dr. Wender and colleagues write.
On the positive side, screening could detect lung cancer at an earlier stage and therefore save lives; on the negative side are limitations and potential harms, including the "relatively high" level of false-positive findings and the resultant anxiety and need for additional invasive tests (such as lung biopsy). In the NSTL, 96.4% of the postive screening results in the LDCT group and 94.5% in the radiography (control) group were false-positive results.
In addition, there is "a legitimate concern" that some smokers will view the chance to undergo screening as an excuse to continue smoking, Dr. Wender and colleagues note. They emphasize that "vigorous smoking cessation efforts must accompany LDCT screening for adults who are current smokers."
Another issue concerns payment. Currently, very few government or private insurance programs provide coverage for the initial LDCT for lung cancer screening.
Advice to Clinicians
The ACS guidelines outline specific recommendations for clinicians.
They advise that clinicians review the smoking history of all patients 55 to 74 years of age to identify those who are in relatively good health but who have a history of smoking (at least 30-pack-year) and currently smoke or have quit smoking in the previous 15 years.
Having identified these individuals, clinicians who have access to high-volume, high-quality lung cancer screening and treatment centers should initiate a discussion about lung cancer screening. This should include a discussion about potential benefits and harms, limitations, and for current smokers should include counseling on smoking cessation.
The guidelines emphasize that clinicians should not discuss lung cancer screening with individuals who do not meet the above requirements.
"Wherever possible, individuals who choose to undergo lung screening should enter an organized screening program at an institution with expertise in LCDT screening, with access to a multidisciplinary team skilled in evaluation, diagnosis, and treatment of abnormal lung lesions, " the guidelines advise.
They recommend that "if an organized, experienced screening program is not accessible, but the patient strongly wishes to be screened, they should be referred to a center that performs a reasonably high volume of lung CT scans, diagnostic tests, and lung cancer surgeries."
"If such a setting is not available, and the patient is not willing or able to travel to such a setting, the risks of cancer screening may be substantially higher than the observed risks associated with screening in the NSTL, and screening is not recommended," according to the guidelines.
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