What are the criteria for lung cancer screening?

Lung Cancer Screening Criteria

Lung cancer screening is recommended for individuals aged 50-80 years with at least a 20 pack-year smoking history who currently smoke or have quit within the past 15 years. 1

Core Eligibility Criteria

The current lung cancer screening criteria have evolved over time, with recent guidelines expanding eligibility to include more at-risk individuals:

• Age: 50-80 years 1, 2
• Smoking history: ≥20 pack-years 1, 2
• Smoking status: Current smokers or former smokers who quit within the past 15 years 1, 2
• Health status: Individuals should be asymptomatic and in relatively good health, able to undergo potential treatment if cancer is detected 3

Screening Method

• Low-dose computed tomography (LDCT) is the recommended screening modality 3
• Chest X-ray is NOT recommended for lung cancer screening 3

Risk-Based Modifications

Individuals who don't meet the standard criteria but have additional risk factors may still benefit from screening starting at age 50 with a lower smoking threshold (≥20 pack-years) if they have any of the following 1:

• Family history of lung cancer in a first-degree relative
• Personal history of COPD or pulmonary fibrosis
• Occupational exposure to carcinogens (asbestos, arsenic, silica, etc.)
• Previous radiation therapy to the chest
• Previous cancer history
• Environmental exposures (e.g., radon)

Implementation Requirements

For optimal screening outcomes, the following conditions should be met:

• Screening should be conducted in high-volume, high-quality lung cancer screening centers 3
• Patients should undergo shared decision-making that includes information about potential benefits, limitations, and harms of screening 3
• Current smokers should receive evidence-based smoking cessation counseling 3
• A multidisciplinary team should be involved in the screening program 2

When to Discontinue Screening

Screening should be discontinued when:

• The individual reaches age 80 1
• Life expectancy becomes limited 1
• The individual is unwilling or unable to undergo curative treatment 1
• For former smokers, when they have quit smoking for more than 15 years (unless they have additional risk factors) 3

Evolution of Guidelines

It's important to note that lung cancer screening guidelines have evolved significantly:

• Earlier guidelines (2013-2015) recommended screening starting at age 55 with a 30+ pack-year smoking history 3
• Current guidelines (2021-2023) have lowered the age threshold to 50 years and reduced the smoking history requirement to 20+ pack-years 1, 2, 4

This expansion of eligibility criteria is estimated to increase screening eligibility (20.6%-23.6% vs 14.1% of the population), increase lung cancer deaths averted (469-558 per 100,000 vs 381 per 100,000), and increase life-years gained (6018-7596 per 100,000 vs 4882 per 100,000) compared to previous guidelines 4.

Potential Harms and Considerations

While screening offers significant mortality benefits, providers should be aware of potential harms:

• False-positive results requiring follow-up testing
• Overdiagnosis of indolent cancers
• Radiation exposure from repeated CT scans
• Anxiety and psychological distress from positive findings

The expanded criteria are estimated to result in more false-positive test results, overdiagnosed lung cancer cases, and radiation-related lung cancer deaths compared to previous guidelines, but the mortality benefit outweighs these harms 4.