Heart failure was not associated with an increased risk of cancer in a study of almost 30,000 men despite previous reports linking the two conditions.
Senthil Selvaraj, MD, MA, and colleagues studied a cohort from the Physicians’ Health Studies (PHS) I and II who were free of cancer and heart failure at baseline. Over a median follow-up of 19.9 years, 1,420 developed heart failure and 7,363 developed cancer.
There was no significant link between the two conditions in either crude or multivariable-adjusted analyses, or when running separate analyses based on the presence of the diseases at the ages of 65, 70, 75 and 80.
“Previous studies showed an increased risk of cancer among HF participants with adjusted HRs (hazard ratios) ranging from 1.68 to 2.16, and another study with an incidence rate ratio of 1.24 (95% CI: 1.05 to 1.24) after adjusted Poisson regression,” wrote Selvaraj, with the Hospital of the University of Pennsylvania, and colleagues. “These studies, however, may have been limited by unadjudicated outcomes, shorter follow-up duration, lack of comprehensive data on shared risk factors, including alcohol and smoking, and potential for confounding by age, which is typically greater in cohort members with HF than in those without. Further, the PHS had a smaller proportion of current and former smokers compared with others, which may reduce residual confounding by smoking status.”
Selvaraj et al. noted their findings may not be generalizable to women, although previous studies didn’t indicate much of a sex-specific difference in the intersection between heart failure and cancer. The study also relied on self-reporting through questionnaires, though its physician cohort would be expected to provide relatively accurate data.
Finally, the researchers said there was a need for further studies to determine whether cancer and heart failure share any pathologies or are entirely separate.
“Though our study did not support an association between HF and cancer, it would be useful to understand whether the immune mechanisms that underlie cardiovascular disease, particularly HF, and cancer are shared or distinct,” they wrote. “Our results seem to support that, while inflammation may be important in both processes, the immune mechanisms of disease development in HF and cancer may actually be distinct.”
In an accompanying editorial, Paolo Boffetta, MD, MPH, and Jyoti Malhotra, MD, MPH, said using ejection fraction and the severity of heart failure in the analysis should be the preferred approach over self-reporting in future studies. They pointed out the findings by Selvaraj et al. suggest heart failure and cancer may share risk factors but not a causal relationship.
However, they agreed with the researchers that additional studies are warranted.
“The association between HF and cancer risk is an important question that has significant clinical implications, including the need for increased cancer screening in patients with HF,” Boffetta and Malhotra wrote. “Therefore, we need additional, larger studies to look at this question, and we also need to include cancer as one of the outcomes in HF trials.”
Daniel joined TriMed’s Chicago editorial team in 2017 as a Cardiovascular Business writer. He previously worked as a writer for daily newspapers in North Dakota and Indiana.