While most people have heard about cancer in other organs, such as the lungs, kidneys, bladder, prostate, breasts and others, you hardly ever hear about cancer of the heart.

That’s because heart cancer — that is, a primary tumor that develops in the heart, as opposed to cancerous cells that spread there from elsewhere in the body — is extremely rare.

The reason is the difference between the types of cells that comprise the heart compared to those that make up the rest of the body.

The vast majority of our trillions of cells divide, which is what keeps our body functioning. Cancer occurs when something goes wrong with this cell division process, leading to uncontrolled cell growth and the formation of tumors.

But the cells of the heart do not replicate like those in the rest of the body.

So although it is possible for cancer to occur, as noted it is exceedingly rare.