Six-Month Smoking Cessation and Cancer-Related Mortality in Patients with Cancer

Background: Smoking cessation after a cancer diagnosis has been associated with improved prognosis.However, real-world evidence on the effectiveness of smoking cessation programs for patients with cancer remains limited.This study aimed to evaluate smoking cessation outcomes at 6 months and examine their association with cancer-related mortality among patients enrolled in a hospital-based smoking cessation program.Methods: Electronic medical records of patients with solid tumors were retrospectively reviewed.Multivariable regression models were employed to identify factors associated with 6-month smoking cessation success and cancer-related mortality.Moreover, a 24-week landmark analysis was conducted to address potential immortal time bias.Results: Among 711 patients (mean age, 62.0±9.9 years), 51.3% achieved smoking cessation at 6 months, and 276 (38.8%) died from cancer-related causes.The conventional multivariable Cox analysis showed that successful smoking cessation was associated with lower cancer-related mortality (hazard ratio [HR], 0.42; 95% CI, 0.31-0.56;P<0.001).Advanced cancer stage was strongly associated with increased mortality, with HRs of 4.78, 12.20, and 25.01 for stages II, III, and IV, respectively, compared to stages 0-I.However, in the 24-week landmark analysis, the association between smoking cessation success and cancer-related mortality weakened and was no longer statistically significant (HR, 0.89; 95% CI, 0.62-1.28;P=0.522).Conclusion: Approximately half of the patients achieved smoking cessation at 6 months.Although the survival advantage of smoking cessation was not definitively proven in the landmark analysis, these findings support the continued smoking cessation support as a key component of comprehensive cancer care.