Lown Right Care

Reducing Overuse and Underuse

Lung Cancer Screening: Pros and Cons


Am Fam Physician. 2019 Jun 15;99(12):740-742.

  Related letter: Identify Patients Likely to Benefit from Lung Cancer Screening

  Related letter: Lung Cancer Screening Effective for Reducing Cancer Deaths

Case Scenario

A 70-year-old man had been a heavy smoker until 10 years ago, when he quit after a myocardial infarction. He has hypertension, mild chronic obstructive pulmonary disease, and stable coronary artery disease. He walks half a mile daily without shortness of breath. At his wellness visit, he asks you about lung cancer screening with low-dose chest computed tomography (CT), because he has been told by a friend that having this test performed annually will reduce his risk of dying from lung cancer by 20%. You inform him that lung cancer screening also has risks, but the patient elects to proceed with the test anyway. His first scan shows an indeterminate lung nodule that will require additional testing, as well as calcifications in his liver and aorta.


The National Lung Screening Trial showed that one in 320 high-risk patients screened with low-dose CT over five years will avoid death from lung cancer. However, no other study has shown a benefit from this screening.

Low-dose CT scans have a high false-positive rate. Of 1,000 high-risk patients who do not have cancer, 250 will have an abnormal low-dose CT result and will require further testing to rule out cancer; 2.5% of patients without cancer will undergo invasive procedures (e.g., lung biopsy, bronchoscopy) with a small risk of complication and death.

Of the cancers found by low-dose CT, at least 20% are overdiagnosed (i.e., the cancer would not have harmed the patient if left alone). Patients with overdiagnosed lung cancers will be exposed to potentially dangerous and lethal interventions with no benefit.

CT = computed tomography.

Clinical Commentary

Lung cancer is the leading cause of cancer death in the United States, accounting for 28% of all cancer deaths.1 The overall five-year survival rate of lung cancer is 17%; however, it rises to 52% if the disease is localized.2 Although screening for lung cancer using chest radiography or sputum cytology is ineffective,3 the 2011 National Lung Screening Trial demonstrated that among people 55 to 74 years of age who actively smoke or have quit smoking within the past 15 years, those who are screened with low-dose CT are less likely to die from lung cancer than those screened with chest radiography. Participants in the trial received three rounds of CT screening and were followed for at least five years.4

The 20% reduction in lung cancer mortality that the patient in the scenario mentioned is based on relative risk; there were 247 lung cancer deaths per 100,000 person-years in the low-dose CT study arm, and 309 lung cancer deaths per 100,000 person-years in the chest radiography arm.4 This relative risk reduction was later recalculated to be 16%.5 A more clinically meaningful number is the absolute risk reduction of approximately three in 1,000 (number needed to screen is 320 to prevent one lung cancer death over five years).4

The U.S. Preventive Services Task Force recommends annual low-dose CT to screen for lung cancer in otherwise healthy adults 55 to 80 years of age who have a 30-pack-year smoking history and currently smoke or have quit within the past 15 years.6 The Centers for Medicare and Medicaid Services pays for annual testing for patients up to age 77, which is the age of the oldest participants in the National Lung Screening Trial.7

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TestRepresentative fair price*

Low-dose CT


Chest CT with contrast


Lung biopsy




Lung surgery


CT = computed tomography; PET = positron emission tomography.

*—The fair price represents reasonable out-of-pocket costs based on price comparisons. Actual cost will vary with insurance and by region.


Address correspondence to Andy Lazris, MD, CMD, at alazris50@gmail.com. Reprints are not available from the authors.

Author disclosure: No relevant financial affiliations.


show all references

1. Ridge CA, McErlean AM, Ginsberg MS. Epidemiology of lung cancer. Semin Intervent Radiol. 2013;30(2):93–98....

2. Moyer VA. Screening for lung cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2014;160(5):330–338.

3. Oken MM, Hocking WG, Kvale PA, et al. Screening by chest radiograph and lung cancer mortality: the prostate, lung, colorectal, and ovarian (PLCO) randomized trial. JAMA. 2011;306(17):1865–1873.

4. Aberle DR, Adams AM, Berg CD, et al.; National Lung Screening Trial Research Team. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365(5):395–409.

5. Pinsky PF. Does the evidence support the implementation of lung cancer screening with low-dose computed tomography? Expert Rev Respir Med. 2018;12(4):257–260.

6. de Koning HJ, Meza R, Plevritis SK, et al. Benefits and harms of computed tomography lung cancer screening strategies: a comparative modeling study for the U.S. Preventive Services Task Force. Ann Intern Med. 2014;160(5):311–320.

7. Centers for Medicare and Medicaid Services. Decision memo for screening for lung cancer with low dose computed tomography (LCDT). https://www.cms.gov/medicare-coverage-database/details/nca-decision-memo.aspx?NCAId=274. Accessed October 2018.

8. American Cancer Society. Lung cancer screening guidelines. https://www.cancer.org/health-care-professionals/american-cancer-society-prevention-early-detection-guidelines/lung-cancer-screening-guidelines.html. Accessed April 10, 2019.

9. Marcus PM. Lung cancer screening with low dose computed tomography (LDCT): looking back and moving forward. Ann Transl Med. 2015;3(suppl 1):S41.

10. American Academy of Family Physicians. Clinical preventive service recommendation: lung cancer. https://www.aafp.org/patient-care/clinical-recommendations/all/lung-cancer.html. Accessed October 2018.

11. Brenner AT, Malo TL, Margolis M, et al. Evaluating shared decision making for lung cancer screening. JAMA Intern Med. 2018;178(10):1311–1316.

12. Bade BC, Brasher PB, Luna BW, Sivestri GA, Tanner NT. Reviewing lung cancer screening: the who, where, when, why, and how. Clin Chest Med. 2018;39(1):31–43.

13. Pastorino U, Rossi M, Rosato V, et al. Annual or biennial CT screening versus observation in heavy smokers: 5-year results of the MILD trial. Eur J Cancer Prev. 2012;21(3):308–315.

14. Usman Ali M, Miller J, Peirson L, et al. Screening for lung cancer: a systematic review and meta-analysis. Prev Med. 2016;89:301–314.

15. Kinsinger LS, Anderson C, Kim J, et al. Implementation of lung cancer screening in the Veterans Health Administration. JAMA Intern Med. 2017;177(3):399–406.

16. Patz EF Jr, Pinsky P, Gatsonis C, et al.; NLST Overdiagnosis Manuscript Writing Team. Overdiagnosis in low-dose computed tomography screening for lung cancer [published correction appears in JAMA Intern Med. 2014;174(5):828]. JAMA Intern Med. 2014;174(2):269–274.

17. Ebell MH, Lin KW. Accounting for the harms of lung cancer screening. JAMA Intern Med. 2018;178(10):1422–1423.

Lown Institute Right Care Alliance is a grassroots coalition of clinicians, patients, and community members organizing to make health care institutions accountable to communities and to put patients, not profits, at the heart of health care.

This series is coordinated by Kenny Lin, MD, MPH, Deputy Editor.



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