Tobacco Smoking and Survival Following a Diagnosis with Ovarian Cancer.

Background: Little is known about the influence of smoking on ovarian cancer survival. We investigated this relationship in a hospital-based study.

Methods: Analyses included 519 women with ovarian cancer. We used multivariable adjusted Cox proportional hazards regression models to estimate HRs and 95% confidence intervals (CI).

Results: Risk of all-cause mortality was increased for current smokers (HR = 1.70; 95% CI: 1.09-2.63) versus never smokers, especially for those with ≥15 cigarettes per day (HR = 1.92; 95% CI: 1.15-3.20). Results were largely similar after additional adjustment for debulking status (current vs. never smokers, HR = 2.96; 95% CI: 1.07-8.21) or neoadjuvant chemotherapy (comparable HR = 2.87; 95% CI: 1.02-8.06). Compared with never smokers, smoking duration ≥20 years (HR = 1.38; 95% CI: 0.94-2.03) and ≥20 pack-years (HR = 1.35; 95% CI: 0.92-1.99) were suggestively associated with worse outcomes. Current smoking was also positively associated with the risk of mortality among patients with ovarian cancer recurrence (current vs. never/past smokers, HR = 2.79; 95% CI: 1.44-5.41), despite the null association between smoking and recurrence (HR = 1.46; 95% CI: 0.86-2.48). Furthermore, no association was observed for smoking initiation before age 18 (HR = 1.22; 95% CI: 0.80-1.85), or either environmental smoke exposure at home (HR = 1.16; 95% CI: 0.76-1.78) or at work (HR = 1.10; 95% CI: 0.75-1.60).

Conclusions: Our results suggest active tobacco smoking is associated with worse ovarian cancer outcomes, particularly after a recurrence.

Impact: Our findings support structured smoking cessation programs for patients with ovarian cancer, especially in recurrent settings. Further research to confirm these findings and examine the interplay between smoking and the tumor immune microenvironment may help provide insight into ovarian cancer etiology.