BACKGROUND Heart failure (HF) and cancer are currently two leading causes of mortality, and sometimes coexist. However, the relationship between them is not completely elucidated. We aimed to investigate whether patients with HF are predisposed to cancer development using the large Korean National Health Insurance claims database.

METHODS This study included 128,441 HF patients without a history of cancer and 642,205 age- and sex-matched individuals with no history of cancer and HF between 1 January 2010 and 31 December 2015.

RESULTS During a median follow-up of 4.06 years, 11,808 patients from the HF group and 40,805 participants from the control were newly diagnosed with cancer (cumulative incidence, 9.2% vs. 6.4%, p < 0.0001). Patients with HF presented a higher risk for cancer development compared to controls in multivariable Cox analysis [hazard ratio (HR) 1.64, 95% confidence interval (CI) 1.61-1.68]. The increased risk was consistent for all site-specific cancers. To minimize potential surveillance bias, additional analysis was performed by eliminating participants who developed cancer within the initial 2 years of HF diagnosis (i.e. 2-year lag analysis). In the 2-year lag analysis, the higher risk of overall cancer remained significant in patients with HF (HR 1.09, 95% CI 1.05-1.13), although the association was weaker. Among the site-specific cancers, three types of cancer (lung, liver/biliary/pancreas, and hematologic malignancy) were consistently at higher risk in patients with HF. An exploratory analysis showed that patients with repeated HF hospitalization had a higher risk of cancer development compared to those without, in a pattern of stepwise increases across the three groups [controls vs. HF without re-hospitalization vs. HF with re-hospitalization ≥1; HR (95% CI), 1.00 (reference) vs. 1.55 (1.51-1.59) vs. 1.96 (1.89-2.03), respectively].

CONCLUSIONS Cancer incidence is higher in patients with HF than the general population. Active surveillance of coexisting malignancy needs to be considered in these patients.