The American Cancer Society has updated its screening guidelines for lung cancer, the leading cause of cancer-specific deaths in the United States and the largest driver of potential years of life lost from cancer.
The 2023 screening guidance, aimed principally at reducing lung cancer mortality in asymptomatic but high-risk, tobacco-exposed individuals, expands the age eligibility and lowers both the former smoking history and the years since quitting threshold for screening with low-dose CT (LDCT).
Dr. Robert A. Smith
It is based on the most recent evidence on the efficacy and effectiveness of screening and lung cancer risk in persons who formerly smoked, wrote the ACS’s Guideline Development Group led by Robert A. Smith, PhD, senior vice president of early cancer detection science. The new guidelines, which replace the 2013 statement, appear in CA: A Cancer Journal for Physicians.
The primary evidence source for the update was a systematic review of LDCT lung cancer screening conducted for the U.S. Preventive Services Task Force and published in 2021.
The new guideline continues a trend of expanding eligibility for lung cancer screening, which has had low uptake, to prevent more deaths. “Recent studies have shown that extending the age for persons who smoked and formerly smoked, eliminating the ‘years since quitting’ requirement, and lowering the pack-per-year recommendation could make a real difference in saving lives,” Dr. Smith said. “The relative risk of developing lung cancer in people who have smoked most of their life compared to people who never smoked is very high – about 70 times the risk.” Although lung cancer is the third most common malignancy in the United States, it accounts for more deaths than colorectal, breast, prostate, and cervical cancers combined.
The recommendation for annual LDCT for at-risk persons remains unchanged from 2013.
Among the 2023 eligibility changes:
- Age: Expanded to 50-80 years from 55-74 years.
- Smoking status: Changed to current or previous smoker from current smoker or smoker who quit within past 15 years (number of years since quitting no longer a criterion to start or stop screening). Dr. Smith noted that both the 2013 guidelines and other groups’ updated recommendations retained the eligibility cutoff of 15 years since smoking cessation. “But had their risk declined to a level that just did not justify continuing screening?” he asked. “There wasn’t an answer to that question, so we needed to look carefully at the absolute risk of lung cancer in persons who formerly smoked compared with people who currently smoked and people who never smoked.”
- Smoking history: Reduced to 20 or more pack-years (average of 20 cigarettes a day) versus 30 or more pack-years.
- Exclusions: Expanded to health conditions that may increase harm or hinder further evaluation, surgery, or treatment; comorbidities limiting life expectancy to fewer than 5 years; unwillingness to accept treatment for screen‐detected cancer, which was changed from 2013’s life‐limiting comorbid conditions, metallic implants or devices in the chest or back, home oxygen supplementation.