Survival among US adults with post-cancer-diagnosis cigarette smoking cessation

Current evidence on the impact of post-cancer-diagnosis cigarette smoking cessation on survival is largely based on small-scale studies with limited cancer types.

This retrospective cohort study included 8,120 adult cancer survivors from the 2000-2018 National Health Interview Survey Public-use Linked Mortality Files with death information through December 31, 2019. We performed propensity score weighting (PSW) and survival analysis to assess the association of smoking cessation within 3 years after a cancer diagnosis with all-cause mortality among adult cancer survivors of all cancer types, cancers with high relative survival rates, and four major cancers (lung, breast, prostate, and colorectal).

Approximately 19.6% of cancer survivors who were cigarette smokers quit smoking within 3 years after their cancer diagnosis. Compared to those who did not quit, cancer survivors who quit had an additional median survival time (MST) of 4 (95% CI 3.1-4.9) years and a relatively lower risk of death (marginal hazard ratio (MHR) 0.86; 95% CI 0.76-0.98). A more pronounced survival benefit was found for survivors of cancers with a high 5-year relative survival rate (> 74%), where the quit group had a longer MST of 7 (95% CI 6.7-7.3) years and an MHR of 0.79 (95% CI 0.66-0.94). Except for colorectal cancer, significant survival benefits were also found for survivors of lung, prostate, and breast cancers.

By integrating PSW with linked nationally representative data spanning nearly two decades, we demonstrated that smoking cessation within 3 years after a cancer diagnosis was associated with a significant survival advantage.