Scientists have named heart cancer the rarest cancer
Cancer can develop in almost any organ of the human body, but the heart remains one of the rarest places of occurrence of malignant tumors. According to statistics, primary heart cancer occurs only in about one in 50,000 people, and if a tumor is still found, then in most cases it turns out to be a metastasis that has spread from another organ. Scientists believe that the secret of this stability lies in the characteristics of the heart itself, from the rate of cell renewal to the constant mechanical stress during contractions. About why the heart is almost never affected by cancer and how this feature can help in the development of new cancer treatment methods — in the Izvestia article.
Not all organs are equally vulnerable: why cancer chooses some tissues more often than others
Skin cancer is considered to be the most common type of cancer: according to experts, approximately one in five people is confronted with it during their lifetime. Lung cancer is much less likely to be diagnosed — about one in 18 people, and liver cancer — about one in 100. Against this background, heart tumors look like an exception: they are so rare that many researchers are trying to understand what exactly protects this organ from the development of the disease.
Any cancer is based on mutations. The human body constantly renews cells: old and damaged ones are replaced with new ones, so that the tissues continue to function normally. However, sometimes errors occur during such an update. If a mutation affects the mechanisms that control cell growth, they begin to divide much more actively than the body needs. Gradually, excess tissue is formed, which consumes the body's resources and disrupts the functioning of healthy organs. This is how cancer develops.
According to the authors of an article in the journal Popular Science, the likelihood of such errors is directly related to how actively cells are being renewed in a particular tissue. The more often cells divide, the more likely it is that one day a dangerous mutation will occur during the division process. That is why some organs are more vulnerable to cancer than others.
Scientists explain the influence of certain bad habits on the risk of developing cancer by the same principle. For example, smoking permanently damages the tissues of the lungs, throat, and mouth. The body has to actively repair damaged cells, which means that the number of cycles of their division increases. The more such cycles there are, the higher the probability of a mutation that can later lead to the development of a tumor.
An organ that has almost no cancer
The main difference between the heart and most other organs is that its cells are updated extremely slowly. If the skin cells are completely replaced approximately every 40-56 days, then the heart muscle cells are restored at a rate of about 1% per year. According to scientists, less than half of the heart cells with which a person was born are naturally renewed over the course of a person's life.
It is this feature, according to the researchers, that largely explains why the heart practically does not become the site of malignant tumors. Since the cells of the heart muscle divide very rarely, the probability of a dangerous mutation is also much lower. As a result, an organ that continuously works throughout a person's life remains one of the most protected from the development of primary cancer.
The authors of the material note that such a slow tissue renewal has become a kind of evolutionary compromise. Thanks to him, the human heart remains strong and is able to effectively perform its function from an early age. However, this reliability had to be "paid for" by the almost complete loss of the ability to regenerate, which was preserved in some other animals.
Thus, certain amphibian species, such as axolotls, are able to repair damaged areas of the heart with virtually no scarring. In mammals, the situation is different. After a serious injury, the heart muscle does not grow new healthy cells in sufficient numbers, but replaces the damaged area with scar tissue. As one scientific paper says, the human heart responds to damage by "repairing rather than regenerating."
Another feature is that even secondary tumors, that is, metastases, relatively rarely affect the heart. This looks especially unusual when you consider that blood flow is considered one of the main ways cancer cells spread through the body. Despite the fact that blood constantly passes through the heart, tumor cells rarely gain a foothold in its tissues, and if this happens, they grow more slowly here than in many other organs.
Heartbeat as a natural defense: what scientists have discovered
Scientists suggest that not only the slow renewal of heart cells plays a protective role. According to a 2026 study, an additional factor may be the constant mechanical pressure that occurs with each heartbeat. According to scientists, it helps to restrain the development of tumor cells in the tissues of the heart.
The reason for this hypothesis was the observation of patients with heart failure. In people who have special devices installed to reduce the load on the heart and help with blood pumping, the cells of the heart muscle begin to renew more actively than usual. Since enhanced regeneration in other body tissues is associated with a higher risk of cancer, scientists have suggested that a similar pattern may exist in the heart.
To test this hypothesis, researchers from the International Center for Genetic Engineering and Biotechnology in Trieste transplanted hearts into mice so that they worked with less stress and experienced lower blood pressure compared to the norm. After that, cancer cells were injected into the transplanted hearts, as well as into the hearts of the control group of animals. The scientists then compared how quickly the tumor cells spread in each case.
The results showed that in the hearts that experienced less mechanical pressure, cancer cells spread much faster. Moreover, the researchers were able to link this effect to the work of a certain protein that is sensitive to the mechanical effects of heart contractions. Under the influence of constant pressure, it reduces the activity of genes associated with tumor growth, thereby hindering the development of malignant cells.
Can this discovery be used to treat cancer?
The authors of the study believe that the discovered mechanism can become the basis for new approaches to cancer therapy. If mechanical pressure is really able to slow down the spread of tumor cells, then in the future it will be possible to try to reproduce this effect artificially.
Scientists call the use of special devices that create rhythmic pressure pulses resembling a heartbeat one of the promising ideas. It is assumed that such impulses will be able to slow down or even stop the spread of tumor cells in certain areas of the body. According to Popular Science, the first prototypes of such devices are already being tested in the treatment of tumors located close to the surface of the body, for example, in some forms of breast cancer.
At the same time, the researchers emphasize that it is premature to talk about the emergence of a new treatment method. The results obtained only help to better understand why the heart remains one of the most resistant organs of the human body to cancer. At the same time, they open up a new line of research that may help in the future to develop ways to slow down the growth of tumors and the spread of metastases.
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