Gastrointestinal bleeding and the risk of colorectal cancer in anticoagulated patients with atrial fibrillation. (7th February 2020)

• Record Type: Journal Article
• Authors: Rasmussen, Peter Vibe; Dalgaard, Frederik; Gislason, Gunnar Hilmar; Brandes, Axel; Johnsen, Søren Paaske; Grove, Erik Lerkevang; Torp-Pedersen, Christian; Dybro, Lars; Harboe, Louise; Münster, Anna-Marie Bloch; Pedersen, Lasse; Blanche, Paul; Pallisgaard, Jannik Langtved; Hansen, Morten Lock
• Is Part Of: European heart journal. Volume 43:Number 7(2022)
• Page Start: e38
• Page End: e44
• Publication Date: 2020-02-07
• Subjects: Atrial fibrillation -- Oral anticoagulation -- Gastrointestinal bleeding -- Colorectal cancer; Cardiology -- Periodicals; Heart -- Diseases -- Periodicals; 616.12005
• DOI: 10.1093/eurheartj/ehz964
• Languages: English
• ISSNs: 0195-668X

Abstract

Abstract: Aims: Gastrointestinal bleeding (GI-bleeding) is frequent in patients with atrial fibrillation (AF) treated with oral anticoagulation (OAC) therapy. We sought to investigate to what extent lower GI-bleeding represents the unmasking of an occult colorectal cancer. Methods and results: A total of 125 418 Danish AF patients initiating OAC therapy were identified using Danish administrative registers. Non-parametric estimation and semi-parametric absolute risk regression were used to estimate the absolute risks of colorectal cancer in patients with and without lower GI-bleeding. During a maximum of 3 years of follow-up, we identified 2576 patients with lower GI-bleeding of whom 140 patients were subsequently diagnosed with colorectal cancer within the first year of lower GI-bleeding. In all age groups, we observed high risks of colorectal cancer after lower GI-bleeding. The absolute 1-year risk ranged from 3.7% [95% confidence interval (CI) 2.2–6.2] to 8.1% (95% CI 6.1–10.6) in the age groups ≤65 and 76–80 years of age, respectively. When comparing patients with and without lower GI-bleeding, we found increased risk ratios of colorectal cancer across all age groups with a risk ratio of 24.2 (95% CI 14.5–40.4) and 12.3 (95% CI 7.9–19.0) for the youngest and oldest age group of ≤65 and >85 years, respectively. Conclusion: In anticoagulated AF patients, lower GI-bleeding conferred high absolute risks of incident colorectal cancer. Lower GI-bleeding should not be dismissed as a benign consequence of OAC therapy but always examined for a potential underlying malignant cause.