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 due to smoking cessation efforts and advances in therapy and early detection. 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 that there will be 238,340 new cases of lung cancer in 2023 and that 127,070 people will die from the disease, accounting for approximately 20% of all cancer deaths, with most of those deaths (about 80%) due to smoking.
A new lung cancer screening guideline from the ACS provides screening guidance to health-care providers and their patients who are at high risk for developing lung cancer due to a history of smoking. The 2023 lung cancer screening guideline—published by Wolf et al in CA: A Cancer Journal for Clinicians—recommends beginning annual screening with low-dose computed tomography (CT) in asymptomatic individuals aged 50 to 80 years old who currently smoke or formerly smoked and have a 20-year or greater pack-year history of smoking. The new guideline also extends the previous recommendation for screening age eligibility (55 to 74 years), eliminates the “years since quitting” requirement, and lowers the pack-year recommendation.
Screening Guideline Methodology
To develop the 2023 guideline, scientists from the ACS Guideline Development Group (GDG) utilized a systematic review of the lung cancer screening literature commissioned for the U.S. Preventive Services Task Force 2021 lung cancer screening recommendation update; 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 and aging on lung cancer risk; and an updated analysis of benefit-to-radiation risk ratios from lung cancer screening and follow-up examinations.
The GDG also 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 judgement (incorporating values and preferences) about the balance of benefits and harms.
Results
The GDG concluded that 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 years is associated with a reduction in lung cancer deaths, according to the research, and inferential evidence support lung cancer screening for individuals older than 80 years who are in good health. The ACS recommendations include:
- Annual lung cancer screening with low-dose CT for asymptomatic individuals aged 50 to 80 years who currently smoke or formerly smoked and have a ≥ 20 pack-year smoking history (strong recommendation, moderate quality of evidence). 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.
- 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 study authors, visit acsjournals.onlinelibrary.wiley.com.
