Lung cancer diagnosis and mortality beyond 15 years since quit in individuals with a 20+ pack‐year history: A systematic review

Abstract

Current US lung cancer screening recommendations limit eligibility to adults with a pack‐year (PY) history of ≥20 years and the first 15 years since quit (YSQ). The authors conducted a systematic review to better understand lung cancer incidence, risk and mortality among otherwise eligible individuals in this population beyond 15 YSQ. The PubMed and Scopus databases were searched through February 14, 2023, and relevant articles were searched by hand. Included studies examined the relationship between adults with both a ≥20‐PY history and ≥15 YSQ and lung cancer diagnosis, mortality, and screening ineligibility. One investigator abstracted data and a second confirmed. Two investigators independently assessed study quality and certainty of evidence (COE) and resolved discordance through consensus. From 2636 titles, 22 studies in 26 articles were included. Three studies provided low COE of elevated lung cancer incidence beyond 15 YSQ, as compared with people who never smoked, and six studies provided moderate COE that the risk of a lung cancer diagnosis after 15 YSQ declines gradually, but with no clinically significant difference just before and after 15 YSQ. Studies examining lung cancer‐related disparities suggest that outcomes after 15 YSQ were similar between African American/Black and White participants; increasing YSQ would expand eligibility for African American/Black individuals, but for a significantly larger proportion of White individuals. The authors observed that the risk of lung cancer not only persists beyond 15 YSQ but that, compared with individuals who never smoked, the risk may remain significantly elevated for 2 or 3 decades. Future research of nationally representative samples with consistent reporting across studies is needed, as are better data from which to examine the effects on health disparities across different populations.

Racial disparities in staging, treatment, and mortality in non-small cell lung cancer

“…Current work is being done to identify screening eligibility criteria in addition to 20+ pack-years smoking history and 15 years since quitting, that could better identify those at highest risk for the development of lung cancer. Particularly, Kondo et al suggest lung cancer risk not only persist past the 15 year since quitting criteria in current screening guidelines, but that it may remain increased for 2–3 decades ( 40 ). The Sybil model, a radiology-based learning model, has also been shown to predict future lung cancer risk, suggesting that artificial intelligence (AI) could be used in the future to identify people at the highest risk for the development of lung cancer, regardless of smoking history ( 41 ).…”

Screening for lung cancer: 2023 guideline update from the American Cancer Society

“…The GDG requested that the ACS CrEST conduct a systematic review of lung cancer incidence, risk, and mortality beyond YSQ15 in persons with ≥20 pack-years of smoking for this guideline update. 43 The search identified articles through February 14, 2023, and yielded 22 studies from 26 publications. The reviewers concluded that, although the risk of lung cancer declined gradually after cessation compared with continuing smoking, there were no clinically significant differences when comparing individuals in the quit-year categories just before and beyond YSQ15 (six studies, moderate certainty of evidence [COE]).…”

“…The reviewers concluded that, although the risk of lung cancer declined gradually after cessation compared with continuing smoking, there were no clinically significant differences when comparing individuals in the quit-year categories just before and beyond YSQ15 (six studies, moderate certainty of evidence [COE]). 43 Similarly, compared with individuals WOLF ET AL.…”

“…However, despite these limitations, these studies consistently found no statistically and/or clinically significant differences in lung cancer incidence and risk until and beyond 15 YSQ. 43 Most of the literature examined in the CrEST systematic review compared relative risk and outcomes in individuals who formerly smoked versus individuals who currently smoke. Given the importance and emphasis on smoking cessation, this comparison is more common and has provided a strong incentive for individuals to stop smoking-when a person quits smoking, not only does their risk of lung cancer drop within a few years, it also continues to decrease over time relative to a person who continues to smoke, whose risk continues to increase.…”

“…Although the key questions satisfied the evidence needs for the guideline update, it was determined that the YSQ eligibility criteria for LCS should be further evaluated. The GDG commissioned an additional systematic review of evidence on continuing lung cancer risk in individuals who quit smoking conducted by the ACS Cancerrelated Evidence Synthesis Team (CrEST) 43 (see Supporting Materials and Table S4). Also, the GDG requested a study reviewing and updating calculations of the benefit-to-radiation-risk ratios associated with LCS and follow-up imaging using modern ionizing radiation dose levels.…”