What Is Cancer? What Is Cancer

The Cancer Process

Cancer is a disease of cells, the basic building blocks of our bodies. Their lives and behavior are controlled by genetic instructions that are present in every cell of the body. Those instructions tell our cells when and how to grow, reproduce and die.

If those instructions get garbled, a cell might start behaving and reproducing in an uncontrolled way. When that happens, we call it cancer.

How Does a Cell Become Cancerous?

All cancers start from a single cell that undergoes many changes. Some of those changes are permanent alterations to the DNA called mutations.

Luckily, our bodies have a host of defensive strategies for making sure damaged or mutated cells never get the chance to reproduce.

It’s because a potentially cancerous cell has to make it past so many of these natural defenses that the process of cancer development can take a long time—years, even decades. Over our lifetimes, thousands and thousands of damaged cells get disposed of before they can cause any harm.

But if a cell does manage to get past our defenses and start multiplying without control, it can form a mass of abnormal cells called a tumor.

Not all tumors are dangerous. Those that arise and then go quiet are called benign. But malignant or cancerous tumors can spread into surrounding tissues, damaging nearby cells or organs.


What Causes Or Protects Against Cancer?

Cancer is not a single disease, and no single factor is likely to be the cause. Many things contribute to cancer development, but we now know that a significant number of cancers are caused by lifestyle factors like smoking, poor diet, and excess body fat.

Understand what that means: Everyday choices affect our chances of getting cancer. (Chances for many common cancers, like those of the colon, breast, esophagus and others, can be cut dramatically.)

It’s important to understand that individual causes of cancer often interact to increase or decrease risk. This is particularly true for diet, which can influence hormone levels and the chronic inflammation that can in turn influence risk.

Many substances in plant foods can help our natural defenses prevent damage or even repair our cells. Daily physical activity also seems to help prevent some major cancers from developing and even from recurring among survivors. And keeping body fat from building up, especially around the middle, is a great way to help defend against many cancers.

The choices listed on the right side of the diagram above can help protect your cells against damage and lower your risk for cancers. The choices listed on the left side can increase your cancer risk. You can click on the graphic to see a larger image.


Choices and Chances: Daily Habits Make a Difference

Remember: Cancer does not develop all at once. It’s a long process in which damage to the cells or mutations accumulate over many years. That means it’s never too early, and never too late, to start making healthy, protective changes that may slow or halt the process.

  • If you smoke, stop.
  • If you’re inactive, get moving.
  • If you’re overweight, do what you can to get to a healthy, stable weight.
  • And if your diet is low in plant foods, start adding them to your very next meal.

Need help making these healthy changes? Read our three simple guidelines.

Published on 12/31/2099