Bleeding and New Malignancy Diagnoses After Anticoagulation for Atrial Fibrillation: A Population-Based Cohort Study.

Summary

In a population-wide cohort of 119,480 older adults initiating anticoagulation for AF, bleeding was associated with a 4-fold higher hazard of new cancer within 2 years, with marked site-concordant risks (GI HR 15.4, GU 11.8, respiratory 10.1). Cancers detected after bleeding were diagnosed at earlier stages, underscoring bleeding as a clinical signal for prompt malignancy work-up.

Key Findings

• Bleeding after starting AF anticoagulation was associated with a 4.0-fold higher hazard of new cancer within 2 years.
• Marked site-concordant cancer risks: GI HR 15.4, genitourinary HR 11.8, respiratory HR 10.1.
• Cancers diagnosed after bleeding were at earlier stages compared with those without antecedent bleeding.

Clinical Implications

Clinicians should treat bleeding after AF anticoagulation as a red flag warranting timely, site-directed cancer evaluation (e.g., GI/GU/respiratory), potentially improving stage at diagnosis and outcomes.

Limitations

• Observational design with potential residual confounding and reliance on administrative coding for bleeding.
• Generalizability limited to older adults (≥66 years).

Future Directions

Prospective evaluation of standardized cancer work-up pathways triggered by bleeding events and cost-effectiveness analyses; integration into anticoagulation management guidelines.