Lung cancer screening: New evidence, updated guidance
Emerging evidence supports lower thresholds for age and smoking history when screening for lung cancer. Here’s how the USPSTF and others have updated their guidelines in response.
PRACTICE RECOMMENDATIONS
› Recommend annual lung cancer screening for all highrisk adults ages 50 to 80 years using low-dose computed tomography. A
› Do not pursue lung cancer screening in patients who quit smoking ≥ 15 years ago, have a health problem that limits their life expectancy, or are unwilling to undergo lung surgery. A
› Recommend varenicline as first-line pharmacotherapy for smokers who would like to quit. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
Potential harms: False-positives and related complications
Screening for lung cancer is not without its risks. Harms from screening typically result from false-positive test results leading to overdiagnosis, anxiety and distress, unnecessary invasive tests or procedures, and increased costs.19TABLE 26,19-23 lists specific complications from lung cancer screening with LDCT.
The false-positive rate is not trivial. For every 1000 patients screened, 250 people will have a positive LDCT finding but will not have lung cancer.19 Furthermore, about 1 in every 2000 individuals who screen positive, but who do not have lung cancer, die as a result of complications from the ensuing work-up.6
Annual LDCT screening increases the risk of radiation-induced cancer by approximately 0.05% over 10 years.21 The absolute risk is generally low but not insignificant. However, the mortality benefits previously outlined are significantly more robust in both absolute and relative terms vs the 10-year risk of radiation-induced cancer.
Lastly, it is important to note that the NELSON trial and NLST included a limited number of LDCT scans. Current guidelines for lung cancer screening with LDCT, including those from the USPSTF, recommend screening annually. We do not know the cumulative harm of annual LDCT over a 20- or 30-year period for those who would qualify (ie, current smokers).
If you screen, you must be able to act on the results
Effective screening programs should extend beyond the LDCT scan itself. The studies that have shown a benefit of LDCT were done at large academic centers that had the appropriate radiologic, pathologic, and surgical infrastructure to interpret and act on results and offer further diagnostic or treatment procedures.
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