But study only found an association and doesn’t prove that atrial fibrillation causes cancer

WebMD News from HealthDay

By Steven Reinberg

HealthDay Reporter

WEDNESDAY, May 25, 2016 (HealthDay News) — Women with a common heart rhythm abnormality may be at an increased risk of developing cancer, particularly of the colon, a new study suggests.

“We found a significant relationship between atrial fibrillation and cancer,” said lead researcher Dr. David Conen, of the University Hospital in Basel, Switzerland.

But the study cannot prove that atrial fibrillation causes cancer, only that an association exists between them, Conen added.

Among nearly 35,000 healthy women followed for about 20 years, those who developed atrial fibrillation had a 60 percent increased risk of cancer diagnosis, the researchers found.

The association may be due to a real connection between atrial fibrillation and cancer, although this seem less likely than that people have shared risk factors for both conditions, including smoking and obesity, he said.

Men probably have the same risk, he said. “There is no reason to believe the risk isn’t the same in men as in women,” Conen explained.

According to Conen, the best way to reduce the risk of atrial fibrillation or cancer is to lose weight, quit smoking and to exercise. “If you reduce risk factors, you are also going to reduce cancer risk,” he said.

For the study, Conen and colleagues followed nearly 35,000 women aged 45 and older who took part in the Women’s Health Study. The participants did not have atrial fibrillation or other heart problems or cancer when the study began. The women were followed between 1993 and 2013 to see if they developed atrial fibrillation or cancer.

During the follow-up period, 4 percent of the women developed atrial fibrillation and about 15 percent were diagnosed with cancer, the investigators found.

Conen’s team said that atrial fibrillation was a significant risk factor for cancer, even after taking other risk factors into account.

The increased risk was higher within three months after developing atrial fibrillation, but the risk persisted over the long term, and an increased risk of dying from cancer was also seen, according to the study.