Systematic review of smoking relapse rates among cancer survivors who quit at the time of cancer diagnosis

Background: Tobacco cessation, at the time of cancer diagnosis, has been associated with better oncologic outcomes. Cancer diagnosis has been shown to serves as a “teachable moment,” inspiring tobacco cessation. However, the sustainability of abstinence from smoking is understudied. Similarly, there is a paucity of data regarding the utility of behavioral/pharmacologic intervention to support continued smoking cessation. Methods: A systematic literature review was conducted in August 2021 with no date limits. Relevant studies that reported tobacco smoking relapse rates for patients who quit at the time of cancer diagnosis were included. Our literature search identified 1620 articles and 29 met inclusion criteria. The primary endpoint of the study was smoking relapse rate. Secondary outcome was a descriptive assessment of behavioral and pharmacologic interventions to promote continued cessation. Exploratory outcomes included a regression analysis to examine associations between study factors and relapse rates. Results: There were 3021 smokers who quit at the time of cancer diagnosis. Weighted overall relapse rate for the study population was 44 % (range 5–57 %). Interventions to support smoking cessation were employed in 17 of the 29 included studies and protocols were heterogenous, including behavioral, pharmacologic, or mixed intervention strategies. Exploratory analysis demonstrated no association between relapse rates and publication year, gender, or study type. Relapse rates were indirectly associated with age (p = .003), suggesting that younger patients were more likely to relapse. Conclusion: The sustainability of smoking cessation after a cancer diagnosis is understudied, and existing literature is difficult to interpret due to heterogeneity. Relapse rates remain significant and, although many studies have included the employment of an intervention to promote continued cessation, few studies have measured the effect of a protocolized intervention to support abstinence.