Prospective cohort of pre- and post-diagnosis alcohol consumption and cigarette smoking on survival outcomes: an Alberta Endometrial Cancer Cohort Study

Purpose To examine the independent and joint relationships between cigarette smoking and alcohol consumption with survival outcomes after endometrial cancer diagnosis. Methods Pre- and post-diagnosis smoking and drinking histories were obtained from endometrial cancer survivors diagnosed between 2002 and 2006 during in-person interviews at-diagnosis and at similar to 3 years post-diagnosis. Participants were followed until death or January 2022. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with Cox proportional hazards regression for associations with disease-free survival (DFS) and overall survival (OS). Results During a median 16.9 years of follow-up (IQR = 15.5-18.1 years), 152 of the 540 participants had a DFS event (recurrence: n = 73; deaths: n = 79) and 134 died overall. Most participants in this cohort were current drinkers (pre = 61.3%; post = 64.7%) while few were current cigarette smokers (pre = 12.8%; post = 11.5%). Pre-diagnosis alcohol consumption was not associated with survival, yet post-diagnosis alcohol intake >= 2 drinks/week was associated with worse OS compared with lifetime abstention (HR = 2.36, 95%CI = 1.00-5.54) as well as light intake (HR = 3.87, 95% CI = 1.67-8.96). Increased/consistently high alcohol intake patterns were associated with worse OS (HR = 2.91, 95% CI = 1.15-7.37) compared with patterns of decreased/ceased intake patterns after diagnosis. A harmful dose-response relationship per each additional pre-diagnosis smoking pack-year with OS was noted among ever smokers. In this cohort, smoking and alcohol individually were not associated with DFS and combined pre-diagnosis smoking and alcohol intakes were not associated with either outcome. Conclusion Endometrial cancer survivors with higher alcohol intakes after diagnosis had poorer OS compared with women who had limited exposure. Larger studies powered to investigate the individual and joint impacts of cigarette smoking and alcohol use patterns are warranted to provide additional clarity on these modifiable prognostic factors.