Association of Cigarette Use and Substance Use Disorders among US Adults with and without a Recent Diagnosis of Cancer

Background: Few studies have examined substance use disorders (SUDs) in cancer patients and it is unclear whether SUDs differentially impact cigarette smoking in patients with vs. without cancer. This study used epidemiological data to estimate current cigarette smoking prevalence and quit ratios among US adults with and without SUDs by cancer status. Methods: Data were drawn from the 2015–2018 National Survey on Drug Use and Health (n = 170,111). Weighted current smoking prevalence and quit ratios were estimated across survey years by SUDs (with vs. without) and by cancer status (with vs. without). Results: Among those with cancer, current smoking prevalence was higher for those with vs. without SUDs (47% vs. 13%, p < 0.001) and quit ratios lower for those with vs. without SUDs (45% vs. 71%, p = 0.002). A similar pattern was observed in adults without cancer, with higher smoking prevalence (56% vs. 21%, p < 0.001) and lower quit ratios (23% vs. 51%, p < 0.001) observed for those with vs. without SUDs, respectively. In adjusted logistic regressions, the SUD × cancer status interaction was not significant for smoking prevalence or quit ratios (AOR = 1.2; 95% CI: 0.7, 2.1, p = 0.56; AOR = 1.0; 95% CI: 0.5, 2.0, p = 0.91, respectively), though smoking prevalence was lower and quit ratios higher for adults with vs. without cancer (ps < 0.05). Conclusions: Among US adults with and without cancer, individuals with SUDs evidenced higher cigarette smoking and lower quit ratios than those without SUDs. Addressing SUDs and their impact on smoking cessation is critical in cancer patients with implications for improving health and treatment outcomes.