Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Low-Dose CT Screening for Lung Cancer

CHEST; ePub 2018 Jan 25; Mazzone, et al

Low-dose computed tomography (CT) screening for lung cancer results in a favorable but tenuous balance of benefits and harms, according to recent recommendations from an expert panel report. This balance may be impacted by the selection of screen-eligible patients, the quality of imaging and image interpretation, the management of screen detected findings, and the effectiveness of smoking cessation interventions. Key clinical guidelines were addressed resulting in 6 graded recommendations and 9 ungraded consensus-based statements. The recommendations include:

  • For asymptomatic smokers and former smokers aged 55 to 77 years who have smoked ≥30 pack years and either continue to smoke or have quit within the past 15 years, the panel suggests that annual screening with low-dose CT should be offered. (Weak recommendation, moderate-quality evidence)
  • For asymptomatic smokers and former smokers who do not meet the smoking and age criteria in recommendation #1 but are deemed to be at high risk of having/developing lung cancer based on clinical risk prediction calculators, the panel suggests that low-dose CT screening should not be routinely performed. (Weak recommendation, low-quality evidence)
  • For individuals who have accumulated <30 pack years of smoking or are <55 years or >77, or have quit smoking more than 15 years ago, and do not have a high risk of having/developing lung cancer based on clinical risk prediction calculators, we recommend that low-dose CT screening should not be performed. (Strong recommendation, moderate-quality evidence)
  • For individuals with comorbidities that adversely influence their ability to tolerate the evaluation of screen detected findings, or tolerate treatment of an early stage screen detected lung cancer, or that substantially limit their life expectancy, the panel recommends that low-dose CT screening should not be performed. (Strong recommendation, low-quality evidence)
  • The panel suggests that screening programs define what constitutes a positive test on the low-dose CT based on the size of a detected solid or part-solid lung nodule, with a threshold for a positive test that is either 4 mm, 5 mm, or 6 mm in diameter. (Weak recommendation, low-quality evidence)
  • For current smokers undergoing low-dose CT screening, the panel recommends that screening programs provide evidence-based tobacco cessation treatment as recommended by the US Public Health Service. (Strong recommendation, low-quality evidence)

Mazzone PJ, Silvestri GA, Patel S, et al. Screening for lung cancer: CHEST guideline and expert panel report. [Published online ahead of print January 25, 2018]. CHEST. doi:10.1016/j.chest.2018.01.016.


The National Lung Screening Trial (NLST) included 53,452 current or former smokers aged 55-74 with at least a 30-pack year history of cigarette use. Former smokers had to have quit within the past 15 years. Participants were randomized to a baseline and 2 annual low-dose CT scans or CXRs. The results, as initially reported, showed a 20% reduction in lung cancer specific mortality and 7% reduction in overall mortality, favoring low-dose CT screening.1 Four other trials randomized 12,673 patients to either annual LDCT or usual care. One additional screening trial still has pending results. The potential harms, both psychological and physical from anxiety over results to biopsy follow up of results is real—a little over one-third of those screened with LDCT have a nodule identified by the end of the 3-year screening period, with approximately 5% requiring a biopsy, and some of those who had biopsies having complications of the biopsy. The guidelines recommend essentially 2 things—first, that screening the correct population of smokers and former smokers is recommended and, second, that we should be careful to recommend screening only in the defined high-risk group. — Neil Skolnik, MD

1. Aberle DR, Adams AM, Berg CD, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365(5):395-409.

This Week's Must Reads

Increased Water Intake in Premenopausal Women with UTIs, JAMA Intern Med; ePub 2018 Oct 1; Hooton, et al

Adverse Childhood Experiences & Weight Status, J Pediatr; ePub 2018 Oct 1; Davis, Barnes, et al

Prevalence of E-Cigarette Use Among US Adults, Ann Intern Med; 2018 Oct 2; Mirbolouk, et al

Continuous Combined Oral Contraceptives & VTE Risk, JAMA Intern Med; ePub 2018 Oct 1; Li, et al

Wearable Cardioverter-Defibrillator Use After MI, N Engl J Med; 2018 Sep 27; Olgin, et al

Must Reads in Oncology

FIT Performance & Optimal Positivity Thresholds, Ann Intern Med; ePub 2018 Sep 18; Selby, et al

Trends in HPV-Associated Cancers in the US, MMWR; 2018 Aug 24; Van Dyne, Henley, et al

Screening for Cervical Cancer in Primary Care, JAMA; 2018 Aug 21; Kim, Burger, et al

Endometrial Ca Risk with Postmenopausal Bleeding, JAMA Intern Med; ePub 2018 Aug 6; Clarke, et al

Can Mailed FIT Outreach Increase CRC Screening?, JAMA Intern Med; ePub 2018 Aug 6; Coronado, et al