The connection between Afib and cancer
New research from UI Health Care shows an association between atrial fibrillation (Afib) and increased cancer risk, especially in younger patients. While this does not mean Afib causes cancer, it may signal broader health factors affecting the entire body.
A possible link researchers are studying
For years, clinicians have observed that patients with cancer are more likely to develop atrial fibrillation (Afib). But researchers at UI Health Care began asking whether the connection might also work in the opposite direction.
"We have known for a long time that cancer patients go on to develop Afib more often than patients who don't have cancer,” says cardiac electrophysiologist Paari Dominic, MBBS, MPH.
Historically, Afib occurring after a cancer diagnosis was attributed to inflammation from the cancer itself or to cancer treatments such as chemotherapy and radiation. But Dominic and his colleagues, including cardiac electrophysiologist Peter Farjo, MD, MS, wanted to know whether the relationship might reflect something deeper.
They wondered if the same gene mutations cause Afib and cancer. They also wanted to know if there is a common umbrella of gene mutations or risk factors that cause both Afib and cancer. If so, is it a matter of which one gets diagnosed first, then the other one would follow?
To investigate these questions, the team studied patients who were first diagnosed with Afib and had no prior history of cancer. They followed them over time to see if they would develop cancer.
“It turns out that patients who have Afib have a higher risk of developing multiple different cancers compared to patients who don't have Afib,” Dominic says.
Both physicians emphasize that this finding represents an association, not proof of cause and effect.
“We can't say that Afib causes cancer by any means, but there does appear to be a clear association with Afib and cancer,” Farjo says.
What the data revealed across age groups
The research analyzed patients across multiple age groups and followed them for up to 15 years.
“When we looked at patients at different age groups, and with different comorbidities like high blood pressure, diabetes, and coronary artery disease, the patients who had new onset atrial fibrillation upon follow-up tended to have a higher incidence of cancer,” Farjo says.
Using national registry data and matching patients with similar health profiles, the team compared those with Afib to those without.
“When we looked at that and compared patients with Afib and without Afib, the patients with Afib had a significantly higher incidence of cancer,” Farjo says.
Again, this does not mean Afib causes cancer. It means that, in this observational study, Afib and cancer occurred together more frequently than expected.
Why the findings in younger patients matter
Previous studies had focused on adults over age 50. This study expanded the analysis to include patients age 30 to 50.
The association was strongest in the younger group.
“It turns out they actually have a stronger association with cancer than the older patients,” Dominic says.
In fact, Farjo says the risk of cancer incidence in that group was nearly three times the cancer incidence risk in the older group.
Because cancer risk naturally increases with age, identifying this association in younger adults is notable.
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What this means for patients
The findings do not suggest that every patient with Afib will develop cancer in the future. Instead, Afib may serve as a broader health signal.
“Afib is not just a lone arrhythmia disorder,” Farjo says. “It's a marker for a more systemic disease. It can reflect ongoing inflammation, changes in overall health, and conditions that may increase the risk of more serious diseases, including cancer.”
For patients, that means Afib management should extend beyond heart rhythm control alone.
“Treating Afib with a whole body approach is the best way to go,” Farjo says.
- Better blood pressure control
- Improved diabetes management
- Weight loss when appropriate
- Routine exercise
- Treating sleep apnea
- Reducing alcohol use
- Avoiding tobacco
“If you have a diagnosis of Afib, it's important to avoid actions that can cause cancer, like smoking,” Dominic says.
Staying up to date with routine, age-appropriate cancer screening is also important. Don’t skip colonoscopies or any other preventative tests.
What this means for referring providers
Dominic and Farjo do not suggest that the findings are strong enough to change national screening guidelines.
“But, it should lead to a heightened vigilance,” Farjo says.
- Ensuring age-appropriate cancer screening is current
- Carefully evaluating constitutional symptoms
- Reinforcing lifestyle counseling
- Viewing Afib as part of a broader health issues affecting the entire body
Farjo emphasizes that Afib should prompt a comprehensive conversation.
“It acts as a marker of kind of overall health and it's something that should be treated with a whole body approach,” he says.
A moment to take ownership of long-term health
Both physicians describe a new Afib diagnosis as a pivotal moment.
“These markers are moments where we really have the opportunity to turn things around, to take control and change some habits and routines which will help atrial fibrillation and maybe decrease cancer risk sometime in the future,” Farjo says.
For patients and providers alike, the takeaway is not alarm but awareness and a proactive approach to long-term health.
