Prospective Cohort of Pre- and Post-diagnosis Diet with Survival Outcomes: an Alberta Endometrial Cancer Cohort Study
Menée au Canada par questionnaires auprès de 503 patientes ayant survécu à un cancer de l'endomètre (durée médiane de suivi : 16,9 mois), cette étude de cohorte prospective évalue l'association entre l'alimentation avant et après le diagnostic (charge glycémique et caractère inflammatoire des aliments, qualité de l'alimentation), la survie globale et la survie sans maladie
Background: The prognostic relationship between diet and endometrial cancer survival remains largely unknown. We sought to determine pre- and post-diagnosis dietary composition, glycemic load (GL), inflammatory potential (Dietary Inflammatory Index (DII)) and quality (Canadian-Health Eating Index (C-HEI) 2005) associations with disease-free (DFS) and overall survival (OS) among endometrial cancer survivors. Additionally, we assessed associations between dietary changes with OS and explored obesity/physical activity effect modification. Methods: Survivors, diagnosed in Alberta, Canada between 2002-2006, completed past-year, food-frequency questionnaires at-diagnosis (n=503) and three-year follow-up (n=395). Participants were followed to death or January 2022. Cox proportional regression estimated HR (95% confidence intervals (CIs)) for dietary survival associations. Results: During 16.9 median years of follow-up, 138 participants had a DFS event and 120 died. Lower pre-diagnosis GL (HRT1vsT3=0.49, 95%CI=0.25-0.97) and greater post-diagnosis energy intakes (EI) from total- and monounsaturated-fat (HRT3vsT1=0.48, 95%CI=0.26-0.87) were associated with better OS. Higher pre-diagnosis C-HEI, less inflammatory diets and lower added sugar intakes were non-linearly associated with better DFS. Consistently low pre-to-post diagnosis EI from carbohydrates and total-fats were associated with better (HR=0.36, 95%CI=0.18-0.72) and worse (HR=2.26, 95%CI=1.21-4.20) OS, respectively. Decreased pre-to-post diagnosis C-HEI was associated with worse OS. In stratified analysis, healthy diets were most beneficial for survivors with obesity and physical inactivity. Conclusion: Adherence to higher quality dietary patterns were associated with better survival. Impact: Our study provides novel evidence that both pre- and post-diagnosis diet are important prognostic factors for endometrial cancer survivors. Post-diagnosis survival associations with diet composition and quality highlight the potential for future interventions.