It’s no surprise that the word “cancer” strikes fear in most peoples’ minds; after all, the disease classification is notorious for having caused one (1) out of every six (6) deaths worldwide back in 2020.

Most people are familiar with the most common types of cancer seen in patients, such as breast, lung, colon, and prostate cancers. However, one organ in the human body seems to be almost immune to this devastating disease—the heart. What about the heart makes it so rare for tumors to appear within it?

Understanding Cancer

Before we delve into the mystery of heart cancer, let’s take a moment to understand what cancer is. Cancer is a group of diseases characterized by the uncontrolled growth and division of abnormal cells in the body. These cells can invade nearby tissues and spread to other body parts, causing various health problems.

Cancer usually originates in specific types of cells. For instance, breast cancer starts in the breast cells, while lung cancer begins in the cells lining the lungs.

This is where the key lies—the cells that line the heart have one particular property that makes tumors highly unlikely to appear there.

The Heart of the Matter

The heart is an organ that pumps blood throughout the body, delivers oxygen and nutrients to all cells, and removes waste products. Unlike many other organs, the heart primarily comprises a muscle tissue called cardiac muscle.

So, why is this important? Well, one of the critical factors that make the heart resistant to cancer is the type of cells it’s made of. Cardiac muscle cells, also known as cardiomyocytes, are highly specialized, and their primary function is to contract rhythmically to pump blood. These cells cannot divide and replicate, which prevents cancer.

Cell Division and Cancer

Cancer often begins when genetic mutations cause normal cells to divide uncontrollably. The more cell divisions that occur, the higher the chance of accumulating genetic mistakes that can lead to cancer. This is why tissues with high cell turnover rates, such as the skin or the lining of the colon, are more susceptible to cancer.

On the other hand, cardiomyocytes are pretty different: they have an exceptionally low rate of cell division. Most of the cells in your heart are created during fetal development and soon after birth and are known for being mostly incapable of fixing their tissue. (It’s part of why caring for your heart is so essential.) Cardiac cell growth mostly happens via cell expansion—not by cell division, like other regularly replenishing tissues like the skin and digestive tract.

Ultimately, this lower rate of cardiac cell division reduces the chances of genetic mutations and, consequently, the risk of cancer in the heart.

Additionally, while the limited ability of cardiac muscle cells to divide is a significant protective factor, the heart just so happens to be located deep inside the chest, protecting it from external factors that might cause unwarranted genetic mutations to cardiomyocytes.

Wrap Things Up

While heart cancer is sporadic, it’s not impossible. Some cases do exist, often originating from the non-muscle tissue in the heart. This also presents the heart with its own double-edged sword: while its low cell division rate makes it hard for cancer cells to appear there, the same property also makes any damage to its tissues very hard to repair on its own, hence the need for extensive cardiac operative procedures and research.

All in all, the heart’s resistance to cancer is primarily due to the unique characteristics of its cells. This only adds to the specific characteristics of one of our most important internal organs, making it a crucial topic of interest for doctors and medical researchers worldwide.

References

• Cancer. (2022, February 3). World Health Organization; World Health Organization. https://www.who.int/news-room/fact-sheets/detail/cancer
• Matters of the Heart: Why Are Cardiac Tumors So Rare? (2009, February 10). [cgvArticle]. https://www.cancer.gov/types/metastatic-cancer/research/cardiac-tumors
• Nandi, S., & Chaudhary, P. (2017). Why is heart rarely affected by cancer? Journal of Bioanalysis & Biomedicine, 09(01). https://doi.org/10.4172/1948-593X.1000e148