Applied Evidence

Lung cancer screening: New evidence, updated guidance

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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.


› 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




A 51-year-old man presents to your office to discuss lung cancer screening. He has a history of hypertension and prediabetes. His father died of lung cancer 5 years ago, at age 77. The patient stopped smoking soon thereafter; prior to that, he smoked 1 pack of cigarettes per day for 20 years. He wants to know if he should be screened for lung cancer.

The relative lack of symptoms during the early stages of lung cancer frequently results in a delayed diagnosis. This, and the speed at which the disease progresses, underscores the need for an effective screening modality. More than half of people with lung cancer die within 1 year of diagnosis.1 Excluding skin cancer, lung cancer is the second most commonly diagnosed cancer, and more people die of lung cancer than of colon, breast, and prostate cancers combined.2 In 2022, it was estimated that there would be 236,740 new cases of lung cancer and 130,180 deaths from lung cancer.1,2 The average age at diagnosis is 70 years.2

Lung cancer

Screening modalities: Only 1 has demonstrated mortality benefit

In 1968, Wilson and Junger3 outlined the characteristics of the ideal screening test for the World Health Organization: it should limit risk to the patient, be sensitive for detecting the disease early in its course, limit false-positive results, be acceptable to the patient, and be inexpensive to the health system.3 For decades, several screening modalities for lung cancer were trialed to fit the above guidance, but many of them fell short of the most important outcome: the impact on mortality.

Sputum cytology. The use of sputum cytology, either in combination with or without chest radiography, is not recommended. Several randomized controlled trials (RCTs) have failed to demonstrate improved lung cancer detection or mortality reduction in patients screened with this modality.4

Chest radiography (CXR). Several studies have assessed the efficacy of CXR as a screening modality. The best known was the Prostate, Lung, Colon, Ovarian (PLCO) Trial.5 This multicenter RCT enrolled more than 154,000 participants, half of whom received CXR at baseline and then annually for 3 years; the other half continued usual care (no screening). After 13 years of follow-up, there were no significant differences in lung cancer detection or mortality rates between the 2 groups.5

Low-dose computed tomography (LDCT). Several major medical societies recommend LDCT to screen high-risk individuals for lung cancer (TABLE 16-10). Results from 2 major RCTs have guided these recommendations.

Lung cancer screening recommendations from American medical societies

At this time, low-dose computed tomography is the only lung cancer screening modality that has shown benefit for both disease-related and all-cause mortality.

The National Lung Screening Trial (NLST) was a multicenter RCT comparing 2 screening tests for lung cancer.11 Approximately 54,000 high-risk participants were enrolled between 2002 and 2004 and were randomized to receive annual screening with either LDCT or single-view CXR. The trial was discontinued prematurely when investigators noted a 20% reduction in lung cancer mortality in the LDCT group vs the CXR group.12 This equates to 3 fewer deaths for every 1000 people screened with LDCT vs CXR. There was also a 6% reduction in all-cause mortality noted in the LDCT vs the CXR group.12

Continue to: The NELSON trial...


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