Objective:

To evaluate whether former smokers who quit more than 10 years ago still have elevated lung cancer and other-cause mortality, questioning the appropriateness of current cessation-based screening eligibility criteria and its implications for patient care.

Key Findings:

• Former smokers who quit over 10 years ago had elevated other-cause mortality compared to never smokers, indicating a need for reevaluation of screening criteria.
• Current smokers had 2-3 times higher hazards of death from causes other than lung cancer, underscoring the risks of continued smoking.
• Former smokers' risk varied by age at cessation, with significant increases in mortality for those who quit later in life, highlighting the importance of cessation timing.
• Lung cancer mortality did not decrease with longer time since quitting when accounting for cumulative smoking exposure, suggesting persistent risk.
• Absolute rates of other-cause mortality in past-eligible smokers were similar to younger eligible smokers, raising questions about current eligibility thresholds.

Interpretation:

The findings suggest that fixed cessation-based cutoffs for lung cancer screening may not adequately reflect the long-term risk profiles of former smokers, indicating a potential need for revised guidelines.

Limitations:

• The study was observational and did not assess clinical screening outcomes, which limits the applicability of the findings.
• Cox models did not adjust for potential confounders beyond age, sex, and smoking-related variables, which may affect the validity of the results.
• Subgroup estimates, especially among older women, were based on small event numbers, limiting precision and generalizability.
• The cohort had lower smoking prevalence than the general population, which may affect the generalizability of the findings to broader populations.

Conclusion:

The study indicates that former smokers who previously met screening criteria may still have sufficient lung cancer risk to warrant consideration for screening, suggesting a potential need for modifying eligibility criteria, but further research is necessary to validate these findings.