A study by researchers in Germany suggests that patients with heart failure are more likely to develop cancer than those without heart failure.
For the study, the researchers included 100,124 patients with heart failure and an equal number without heart failure in their analysis. Each patient had an average age of 72.6 years old and 54% were women. They were individually matched according to sex, age, obesity, diabetes and frequency of consultation. At the beginning of the study, none of the patients had cancer. They were then observed for 10 years.
Using statistical models, the researchers found that over the study period, 25.7% of heart failure patients developed cancer compared to 16.2% of those without heart failure. Women had higher rates of cancer overall. 28.6% of women with heart failure developed cancer during the period, whereas 18.8% without heart failure did. The corresponding rates for men were 23.2% and 13.8%.
The researchers reported that significant associations were found between heart failure and all types of cancer observed. The greatest increase in risk however was observed for cancer of the lip, oral cavity and pharynx, followed by respiratory organ cancer. Female genital organ cancer, skin tumors and lymphoid and haematopoietic tissue cancer were also more prominent among those with heart failure.
"Our results allow us to speculate that there may be a causal relationship between heart failure and an increased rate of cancer.” says Dr. Mark Luedde, one of the authors behind the study, “This is biologically plausible, as there is experimental evidence that factors secreted by the failing heart may stimulate tumour growth."
Currently, cancer patients who have received drugs that impact their heart are monitored for heart failure. The researchers say that their findings, alongside previous studies, suggest that heart failure patients should also be monitored for cancer development.
Yet, while interesting results, the researchers caution that their study was observational in nature and thus does not prove that heart failure causes cancer. They also added that their database did not include certain lifestyle choices which could have influenced their results such as information on smoking, alcohol consumption and physical activity.