Cancer incidence and mortality in patients diagnosed with heart failure: results from an updated systematic review and meta-analysis

Background Several cohort studies aimed at demonstrating an increased risk of cancer incidence and mortality in patients with a pre-existing diagnosis of heart failure (HF); however, conflicting results have been reported that call for systematic review and meta-analysis. Methods We conducted a systematic search of multiple databases from their inception through July 2022 and retrieved only papers reporting hazard ratios (HR). Random and fixed-effects models were fit for the study duration. Results The analysis included nine cohort studies for a total of 515′041 HF cases and 1′365’452 controls without HF. Although high heterogeneity among studies was observed, the HR for incident cancer in HF patients was statistically significant (1.45, 95% CI 1.31–1.61, p < 0.0001 ), which was confirmed by sensitivity analyses; however, by analyzing the few papers reporting HRs for cancer mortality, no significant difference between HF and non-HF patients could be detected (HR 2.03, 95% CI [0.93–4.43], p = 0.0736 ). Further scrutiny of studies with adjusted HRs, when available, confirmed that cancer incidence was significantly increased in patients with HF, as was cancer mortality as well. Conclusions This meta-analysis shows that HF patients are at an increased risk of incident cancer. Increased mortality could not be firmly demonstrated by the available data. Our results call for inclusion of cancer-related endpoints in HF trials to adequately address this important clinical issue.