Can a Heart Get Cancer?

It’s not nearly as likely as with other organs. Heart cells don’t regenerate like other cells do. If your heart gets cancer, it is likely spread from other organs into the pericardial sac.

Heart cancer is extremely rare. For example, one study reviewed more than 12,000 autopsies and found only seven cases of primary cardiac tumor. At Mayo Clinic, on average only one case of heart cancer is seen each year.

Although still rare, most cancers found in the heart have come from elsewhere in the body. Cancers that begin near the heart, such as lung cancer, can grow to involve the heart or the lining around the heart (pericardial sac). Or cancer can begin elsewhere in the body and spread to the heart through the bloodstream. Cancers that may affect the heart include breast cancer, kidney cancer, lung cancer, leukemia, lymphoma and melanoma, among others.

Cancer can affect the heart in other ways, as well. A rare type of cancer known as carcinoid tumor at times produces hormones that can damage heart valves.

Why the heart can not regenerate itself:

Unlike newts and salamanders, human adults cannot spontaneously regrow damaged organs such as the heart. However, recent research suggests that mammals do have the ability to regenerate the heart for a very brief period, about the first week of life. But that ability is quickly lost. But if we had it once, MacLellan said, maybe it is possible to regain that ability.

Published in the Aug. 8 issue of the peer-reviewed Journal of Cell Biology, MacLellan’s study suggests it might be possible to turn back the cellular clock to a time when cardiac myocytes had the ability to proliferate and re-grow heart muscle.

“These salamanders and other lower organisms have the ability to de-differentiate cardiac myocytes, or take them back to an earlier, more primitive state, which allows them to re-enter the cell cycle, creating new heart muscle,” said MacLellan, who also is an associate professor of cardiology and physiology. “In mammals, we’ve lost that potential. If we knew how to restore that, or knew the reason why adult myocytes can’t do it, we could try to figure out a way to use nature’s methods to regenerate the heart.”

This is also interesting: cancer specifically needs live cells, mitosis (cell division), and blood to survive. Therefore, your nails, hair, and teeth (at least the outer part) can’t develop cancer, and it is extremely rare for cancer to develop in cartilage:

Cancers can only develop from cells which are reproducing and they develop more often in cells which reproduce rapidly. For example the rates of bone cancer, while low overall, are highest in adolescents. Similarly brain tumors come from the glial cells which reproduce often but rarely from neurons which are terminally differentiated. Also access to vasculature is critical to cancer formation which is why cancers of cartilage, a poorly vascularized tissue, are very rare. The only tissues will never develop into cancer are the ones where the cells are already dead hence nails, teeth and hair. In fact its actually only the outer shell of teeth which can’t develop cancer whereas the interior pulp could become transformed.

Do fish get cancer? Yes. Do sharks get cancer? Yes, but their bodies are, remarkably, cancer-inhibitive. As the tumor tries to grow and emits a hormone, the shark body tries to squash it:

A: While it is not true that sharks do not develop cancer, they do have a remarkable cancer shield. Of the thousands of fish tumors in the collections of the Smithsonian Institution, only about 15 are from elasmobranchs (The Smithsonian is an amazing place – where else can one go to see thousands of fish tumors?), and only two of these are thought to have been malignant.

A tumor can be thought of as an uncontrolled cellular growth. To support their very high metabolism, tumors secrete a hormone called ‘angiogenin’ which causes nearby blood vessels to grow new branches that surround the tumor, bringing in nutrients and carrying away waste products (this last is likely to be the mechanism of metastasis – where part of a tumor breaks away and establishes another cancerous colony elsewhere in the body). Research by Dr. Robert Langer of M.I.T. and other workers has revealed a promising anti-tumor agent obtainable in quantity from shark cartilage. Shark cartilage, it turns out, contains a compound antagonistic to the effects of angiogenin, called (cleverly enough) ‘angiogenin inhibitor’ – which does just what it sounds like: inhibits the formation of new blood vessels so that the proto-tumor starves or ‘chokes’ in its own waste products.

Pictured: 13.5-foot hammerhead


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