Constant mechanical force may be why heart cancer is so rare

The human heart beats more than 1 lakh times a day, pushing blood through the body under constant physical strain. Every second, it encounters circulating cells, including cancer cells that travel through the bloodstream. Yet tumours of the heart are strikingly rare.

For decades, scientists have tried to explain this puzzle using genetics, immune surveillance, and the unique biology of heart cells. But these explanations have not resolved the paradox. Now, new research published in Science has pointed in a different direction — suggesting that the force of each heartbeat may itself limit the growth of cancer cells in the organ.

The idea did not begin with cancer but with an unexpected observation in patients with severe heart failure, said Giulio Ciucci, a postdoctoral researcher at the International Centre for Genetic Engineering and Biotechnology, Trieste, Italy, and co-author of the study.