Cancer Is Somehow Rare in the Heart. Turns Out, the Organ’s Rhythmic Beat Might Keep the Disease at Bay, a Mouse Study Finds

Less than 1 percent of cancers start in the heart, and disease that begins elsewhere seldom spreads to the blood-pumping organ. New research suggests mechanical force might have a protective role

Sara Hashemi | Daily Correspondent

May 5, 2026 2:31 p.m.

Share

Copy linkEmailSMSFacebookXRedditLinkedInBlueskyPrint

Add as preferred source

Cancer can occur anywhere in the human body, but it’s rarely found in the heart—a conundrum that has long stumped scientists.

Now, a new study in mice may have figured out why: The mechanical force of a beating heart seems to create an environment that’s inhospitable to cancer. The findings, published April 23 in the journal Science, could help researchers develop new therapies for the disease that rely on mechanical stimulation.

The American Cancer Society estimates that more than two million cancer cases will be diagnosed in the United States this year, but less than 1 percent of them will be cancers of soft tissues, including the heart. Tumors that start in the blood-pumping organ have been found in less than 1 percent of autopsies, and only 10 percent of cancer cases that begin in other locations spread to the heart, according to a 2020 editorial in the Journal of the American Heart Association.

“It’s interesting that [cancer] doesn’t occur that often in the heart. People have not really been sure exactly why, but it’s just something that we accepted,” says Michael Fradley, a cardiologist at Penn Medicine who was not involved in the study, to Anil Oza at STAT. “What makes this article really fascinating is that they have provided a potential mechanism to explain this phenomenon.”

The mammalian heart is also strangely unable to regenerate cells, since they stop dividing soon after birth. To see if this observation related to tumor cells’ inability to grow in the organ, the researchers behind the new study turned to mice.  

These animals were modified so that one of their heart chambers didn’t pump blood. The researchers added a donor heart to each mouse’s neck and hooked it up to the circulatory system so it could take over the nonfunctional “native” heart chamber’s duties. The second heart was under less mechanical stress than the native heart.

Then, the researchers injected cancer cells into both hearts. Analysis revealed that the disease spread through most of the analyzed cells in the transplanted hearts within two weeks. In the same time frame, cancer rarely invaded more than 20 percent of the examined tissue in the native hearts.

The team confirmed the heartbeat’s role using engineered cardiac tissues made from rat cells. Injected cancer cells grew better in artificial tissue that was beating like a standard heart than in still tissue.

“Our findings show that the heart’s pulsation is not merely a physiological function but may act as a natural suppressor of tumor growth,” says study co-author Serena Zacchigna, a clinician-scientist at the University of Trieste in Italy, in a statement. “This suggests that the cardiac environment is unfavorable to cancer cells not only for immunological or metabolic reasons, but also because its continuous mechanical activity physically constrains their expansion.”

What’s more, Zacchigna and her colleagues found that mechanical stress promoted a protein in cancer cells called Nesprin-2, which can modify DNA in response to an outside factor. This is called an epigenetic mechanism. Turning off Nesprin-2 in cancer cells allowed them to grow and spread in beating hearts.

“What’s really striking is this link they provide between mechanical load and epigenetic regulation. They show that these physical forces can directly alter gene expression in cancer cells, which is a powerful concept that extends beyond cardiology,” says Javid Moslehi, a cardiologist at the University of California, San Francisco, who was not involved in the study, to STAT.

Now, the research team is looking into whether the heart’s mechanical forces could be replicated elsewhere in the body, such as the skin and breast, to prevent tumor growth beyond the blood-pumping organ, Zacchigna tells Rachel Fieldhouse at Nature. They’re also investigating if diseases that put additional pressure on the heart, like high blood pressure, might help protect against cancer.

Sara Hashemi | Read More

Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.