Quitting Smoking After a Cancer Diagnosis Extends Survival

Survival among patients who continue smoking after a cancer diagnosis differs substantially depending on whether they engage in smoking cessation. On October 31, 2024, JAMA Oncology published a single-center study in which Cinciripini and colleagues found that cancer patients who took part in a smoking cessation intervention and quit lived longer after diagnosis than those who continued smoking. This finding highlights smoking cessation treatment as a potentially important early intervention for cancer patients.

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Study Details and Findings

This extensive study included 4526 cancer patients who participated in smoking cessation treatment between January 2006 and March 2022. The program was offered through the MD Anderson Cancer Center Tobacco Research and Treatment Program, and patients' smoking status was assessed at 3, 6 and 9 months after enrollment.

Of these patients, 1900 successfully quit smoking, while 2626 continued. The effect of successful cessation on survival was followed for 15 years after the start of the treatment program.

A noticeable improvement in overall survival was found among patients who quit smoking. In particular, survival increased substantially in those who quit within the first 3, 6 and 9 months:

• Those who had quit by 3 months: Survival in this group was 25% higher than in those who had not quit (adjusted hazard ratio [aHR] = 0.75; 95% confidence interval [CI] = 0.67-0.83).
• Those who had quit by 6 months: Survival in this group was 21% higher than in those who had not quit (aHR = 0.79; 95% CI = 0.71-0.88).
• Those who had quit by 9 months: Survival was 15% higher than in patients who had not quit (aHR = 0.85; 95% CI = 0.76-0.95).

The Relationship Between Time to Quitting and Survival

The greatest benefit of smoking cessation was observed when treatment began within the first 6 months after the cancer diagnosis. Survival increased substantially in these patients. For example, survival time at the 75% percentile was 2.1 years (95% CI = 1.8–2.4 years) among those who did not quit, rising to 3.9 years (95% CI = 3.2–4.6 years) among those who did.

Explanation of the graph: Those who quit within the first 6 months (orange line) had substantially higher survival than those who did not (blue line). The greatest improvement in survival appeared in the first years after diagnosis. For those who did not quit , survival time at 75% was approximately 2.1 years according to the calculation. For those who quit , this time increased to approximately 3.9 years of survival. Log-Rank Test: The log-rank test gave P<0.001 , meaning that the difference was statistically significant. This indicates that quitting smoking has a significant effect on survival time.

Study Conclusions and Significance

The study shows that participating in a smoking cessation program during cancer treatment is an important factor in improving survival. The researchers report that evidence-based cessation treatment started within the first 6 months after diagnosis offers the greatest survival benefit. Starting smoking cessation interventions early for patients diagnosed with cancer is therefore extremely important clinically.

This study once again demonstrated that smoking cessation treatment not only improves overall health in people facing cancer but also extends survival. Greater support for cessation interventions in cancer treatment and effective communication of their benefits to patients are essential for improving clinical outcomes and extending patients' lives.