Colorectal Cancer

What Is Colorectal Cancer?

Colorectal cancer is one of the most common cancers in the U.S. today. 90-95% of all colorectal cancers are adenocarcinomas. This is a cancer that begins in cells that make and secrete fluids such as mucus. These cells are in glandular tissue.

To better understand what an adenocarcinoma is, consider the word: Adeno means gland; Carcinoma is a malignant tumor.

Although these tumors are malignant, they all generally start from adenomas. These are polyps that are not cancerous. The bigger the adenoma is, the more likely it is to become cancerous.

Colon polyps are a common occurrence. In fact, 25% of people over age 50 have polyps.

To better understand colorectal cancer facts, it’s first important to understand the definition of cancer: basically, the production of abnormal cells.

The body is programmed to routinely replenish cells in different organs. As normal cells age or get damaged, they die off. New cells take their place. This is what’s supposed to happen. Abnormal cell growth refers to a buildup of extra cells. This happens when:

  • New cells form even though the body doesn’t need them or
  • Old, damaged cells don’t die off.

These extra cells accumulate to form a tissue mass, lump, or growth called a tumor. These abnormal cells can destroy normal body tissue and spread through the bloodstream and lymphatic system.

Next

How Colorectal Cancer Spreads

Before you can understand how colorectal cancer cells can spread, it's important to have a clear picture of the anatomy of your colon.

Colorectal Cancer Diagram