Venous thromboembolism in 5-year cancer survivors: a nationwide cohort study

AIMS: Cancer is associated with a significant short-term risk of venous thromboembolism (VTE). With substantial improvements in cancer survival, concern has been raised about an increased risk of VTE in long-term cancer survivors. We aimed to investigate the long-term risk of VTE in 5-year cancer survivors according to cancer subtype, age, and sex compared with a matched background population. METHODS AND RESULTS: Using Danish nationwide registries, we matched 5-year survivors of 21 cancers (≥18 years; diagnosed 2000-2017; included 2005-2022 [5 years after cancer diagnosis]) with individuals from the background population (1:1 matching for the overall population and 1:4 matching for each cancer subtype). Rates of VTE were examined using Cox regression. In the overall population, 222 297 five-year cancer survivors were matched with 222 297 individuals from the background population (median age 69.2 years; 43.6% males). During a median follow-up of 5.6 years, cancer survivors had a higher associated rate of VTE compared with the background population (adjusted hazard ratio [aHR] 1.85 [95%CI, 1.78-1.93]). Survivors of all 21 cancer subtypes had a higher associated rate of VTE compared with the background population, with the highest incidence rates found for multiple myeloma. HRs were higher in younger cancer survivors compared with older cancer survivors (<50 years: aHR, 2.85 [95%CI, 2.33-3.47]; 50-64 years: aHR, 2.26 [95%CI, 2.07-2.46]; ≥65 years: aHR, 1.69 [95%CI, 1.61-1.77]; Pinteraction<0.0001). Similar HRs were found in females and males (females: aHR 1.84 [95%CI, 1.75-1.95]; males: aHR 1.86 [95%CI, 1.75-1.98]; Pinteraction=0.94). CONCLUSION: Five-year cancer survivors had a higher associated rate of VTE compared with the background population.