Prevalence and incidence of various Cancer subtypes in patients with heart failure vs matched controls

Background: Patients with heart failure (HF) may be at increased risks of cancer, but the magnitude of risk for various cancer subtypes is insufficiently investigated. Method: Using the Danish Nationwide administrative databases between 1997 and 2017, we estimated the prevalence, incidence and relative risk for all-cause cancer in new-diagnosed HF vs. age and sex-matched controls (up to 5 controls per HF case) before and after adjustment for comorbidities. Results: Among the 167,633 people in the heart failure group and 837,126 individuals in the control group, there was a higher prevalence of several comorbidities, including cancer (17% vs. 10%) in the HF group; odds ratio 1.72 (1.70–1.75). Patients with heart failure also had higher cancer incidence (cancer incidence rate 3.02 [2.97–3.07] per 100 person-years), compared with controls (cancer incidence rate 1.89 [1.88–1.90]); hazards ratio 1.38 (1.36–1.40). However, after adjustment for comorbidities the increased risk of malignancy was greatly attenuated (hazards ratio 1.14 [1.12–1.16] for incident all-cause cancer) and dissipated altogether after additional adjustment for medications (multivariable adjusted hazards ratio 0.93 [0.91–0.96] for all-cause cancer). In a homogeneous cohort of patients with ischemic heart disease, the increased risk of all-cause cancer was only marginally increased after adjustment for baseline comorbidities (hazards ratio 1.05 [1.02–1.08]). Conclusion: Patients with heart failure had a slightly increased risk of various cancer subtypes, but the risks were mainly driven by comorbidities.