Lung cancer incidence overall has been declining in the United States since 1992—and since 2006–2007 for both men and women by 2.7% annually and 1.1%, respectively—and overall mortality rates have declined in both men and women because of smoking cessation efforts and advances in therapy and early detection.¹ Nevertheless, lung cancer remains the second most common cancer diagnosed in men and women and the leading cause of cancer death. The American Cancer Society (ACS) estimates there will be 238,340 new cases of lung cancer in 2023 and 127,070 people will die of the disease, accounting for approximately 20% of all cancer deaths,¹ with most of those deaths (about 80%) the result of smoking.²

Robert A. Smith, PhD

A new lung cancer screening guideline from the American Cancer Society provides screening guidance to health-care providers and their patients who are at high risk for developing lung cancer from a history of smoking.³ The 2023 lung cancer screening guideline recommends beginning annual screening with low-dose computed tomography in asymptomatic individuals aged 50 to 80 who currently smoke or formerly smoked and have a 20-year or greater pack-year history of smoking. The new guideline extends the previous recommendation for screening age eligibility, (55–74 years), eliminates the “years since quitting” requirement, and lowers the pack-year recommendation.

Screening Guideline Development Methodology

To develop the 2023 guideline, scientists from the ACS Guideline Development Group used a systematic review of the lung cancer screening literature commissioned for the U.S. Preventive Services Task Force 2021 lung cancer screening recommendation update.⁴ They also employed a second systematic review of lung cancer risk associated with years since quitting smoking; literature published since 2021; two Cancer Intervention and Surveillance Modeling Network–validated lung cancer models to assess the benefits and harms of screening; an epidemiologic and modeling analysis examining the effect of years since quitting smoking and aging on lung cancer risk; and an updated analysis of benefit-to-radiation risk ratios from lung cancer screening and follow-up examinations.

In addition, the Guideline Development Group examined disease burden data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results program. Formulation of recommendations was based on the quality of the evidence and judgment (incorporating values and preferences) about the balance of benefits and harms.

Results

The Guideline Development Group concluded the overall evidence was moderate and sufficient to support a strong recommendation for screening individuals who meet the eligibility criteria. Lung cancer screening in men and women aged 50 to 80 is associated with a reduction in lung cancer deaths, according to the research, and inferential evidence supports lung cancer screening for individuals older than age 80 who are in good health. The ACS recommendations include:

• Annual lung cancer screening with low-dose computed tomography is appropriate for asymptomatic individuals aged 50 to 80 who currently smoke or formerly smoked and have a ≥ 20 pack-year smoking history. (A pack-year is the equivalent of smoking an average of one pack of cigarettes per day for a year; hence, a 20 pack-year smoking history denotes one pack per day for 20 years or two packs per day for 10 years.) This was designated a strong recommendation, with moderate quality of evidence.
• Before the decision to screen is made, individuals should engage in a shared decision-making discussion with a qualified health-care professional.
• For individuals who formerly smoked, the number of years since quitting is not an eligibility criterion to begin or to stop screening.
• Individuals who currently smoke should receive counseling to quit and be connected to cessation resources.
• Individuals with comorbid conditions that substantially limit life expectancy should not be screened.

“These recommendations should be considered by health-care providers and adults at high risk for lung cancer in discussions about lung cancer screening. If fully implemented, these recommendations have a high likelihood of significantly reducing death and suffering from lung cancer in the United States,” concluded the researchers.

Clinical Significance

“This updated guideline continues a trend of expanding eligibility for lung cancer screening in a way that will result in many more deaths prevented by expanding the eligibility for screening to detect lung cancer early,” said Robert A. Smith, PhD, Senior Vice President of Early Cancer Detection Science at the American Cancer Society, and lead author of the lung cancer screening guideline report, in a statement. “Recent studies have shown extending the screening age for persons who smoke and formerly smoked, eliminating the ‘years since quitting’ requirement, and lowering the [pack-year] recommendation could make a real difference in saving lives.” 

DISCLOSURE: Funding for this research was provided by the American Cancer Society Guideline Development Group and the National Comprehensive Cancer Network. For full disclosures of the guideline update authors, visit acsjournals.onlinelibrary.wiley.com.

REFERENCES

1. Siegel RL, Miller KD, Wagle NS, et al: Cancer statistics, 2023. CA Cancer J Clin 73:17-48, 2023.

2. Islami F, Sauer AG, Miller KD, et al: Proportion and number of cancer cases and deaths attributable to potentially modifiable risk factors in the United States. CA Cancer J Clin 68:31-54, 2018.

3. Wolf AMD, Oeffinger KC, Shih TYC, et al: Screening for lung cancer: 2023 Guideline update from the American Cancer Society. CA Cancer J Clin. November 1, 2023 (early release online).

4. U.S. Preventive Services Task Force: Final Recommendation Statement: Lung Cancer: Screening, March 9, 2012. Available at www.uspreventiveservicestaskforce.org/uspstf/recommendation/lung-cancer-screening. Accessed November 16, 2023.