Evidence is sufficient to recommend screening high-risk patients for lung cancer with low-dose computed tomography, provided that certain conditions exist, according to new guidelines from the American Cancer Society.
Patients should be age 55 to 74 and have at least a 30-pack-year smoking history, and currently smoke or have quit within the past 15 years. Pack-years are calculated by multiplying the number of packs of cigarettes smoked per day by the number of years the person has smoked.
In addition, patients should have a thorough discussion beforehand of the benefits, limitations and risks of screening, and should be screened in a setting with experience in lung cancer screening.
Following the announcement of results from the National Lung Cancer Screening Trial in late 2010, the American Cancer Society joined with the American College of Chest Physicians, the American Society of Clinical Oncology and the National Comprehensive Cancer Network to produce a systematic review of the evidence related to lung cancer screening with low-dose CT.
The systematic review focused on four key questions: What are the potential benefits of screening individuals at high risk of developing lung cancer using LDCT? What are the potential harms of screening individuals at high risk of developing lung cancer using LDCT? Which groups are likely to benefit or not benefit? And in what setting is screening likely to be effective?
The results of the systematic review are used as the basis for the new recommendations, which appeared Jan. 11 on the website of CA: A Cancer Journal for Clinicians, a peer-reviewed journal of the American Cancer Society.
“Findings from the National Cancer Institutes National Lung Screening Trial established that lung cancer mortality in specific high-risk groups can be reduced by annual screening with low-dose computed tomography,” the authors wrote. “These findings indicate that the adoption of lung cancer screening could save many lives.”
The authors cautioned that more work is needed to fill in existing knowledge gaps related to broadening eligibility for lung cancer screening. Researchers and policymakers should seek to further define early lung cancer detection protocols and put in place an infrastructure to support population-based lung cancer screening. “As with other guidelines for cancer screening, we can expect that this initial guideline will be revised as new data become available.”
As with other cancer screening recommendations, the new lung cancer screening guidance embraces the process of informed and shared decision-making, including a thoughtful discussion with a clinician related to the potential benefits, limitations and harms associated with screening. This discussion should occur before any decision is made to initiate lung cancer screening.
Among the limitations and harms posed by screening are missed cancers, anxiety associated with abnormal results, the need for additional imaging tests and biopsies, investigation of incidental findings not related to the lungs and exposure to radiation from repeated tests.
The recommendations emphasize that smoking cessation counseling remains a high priority for clinical attention in discussions with current smokers, and that screening should not be viewed as an alternative to smoking cessation.
The hope is that the guideline will lead adults at high risk of lung cancer to become informed about the potential to detect lung cancer early and to be referred to institutions that can deliver high-quality services, and that screening will contribute to additional declines in lung cancer mortality.
However, the authors cautioned that the implementation of high-quality lung cancer screening in the U.S. poses many challenges: “Whether community-based screening for lung cancer with LDCT will exceed or fail to achieve the benefit observed in the NLST could be influenced by many factors, and the answer awaits the results of further observation and research.”
The full report of the new guidelines is available at http://onlinelibrary.wiley.com/doi/10.3322/caac.21172/full.