Heart failure (HF) and cancer share common risk factors, and previous studies have indicated that patients with HF have an increased risk of cancer. However, a new study reports that the presence of HF has no effect on the incidence of cancer or on cancer-specific mortality. The study included data from 28,341 male participants from the Physicians’ Health Studies I and II. During a median follow-up of almost 20 years, 1,420 patients developed HF and 7,363 cancers developed. The investigators used time-varying analysis (in which HF was modelled as a time-varying exposure) and landmark analysis methods to minimize possible confounding by age, the strongest risk factor for cancer. HF was not associated with the overall incidence of cancer in either unadjusted or multivariable-adjusted models, or with site-specific cancer or cancer-specific mortality after multivariable adjustment. Nevertheless, as Paolo Boffetta and Jyoti Malhotra caution in an accompanying editorial, larger studies are needed before completely disregarding the potential association between HF and cancer.