What is Colorectal Cancer?

Colorectal cancer starts in the colon or rectum, the last parts of our digestive system where the body processes food and expels waste. Most colorectal cancers begin as small growths called polyps. While polyps are generally non-cancerous, some types can turn into cancer over time if they aren’t detected and removed. The good news? With regular screening, doctors can often find and remove polyps before they cause any problems.

Colorectal Cancer: Who’s at Risk?

Colorectal cancer is one of the most common types of cancer, and certain people are at higher risk. Risk factors include age, family history, lifestyle choices (like diet and exercise), and conditions like inflammatory bowel disease (IBD). Some genetic conditions, such as Lynch syndrome, also increase colorectal cancer risk. Understanding these factors can help you make informed choices about screening and prevention.

Anatomy of the Colon and Rectum

To better understand colorectal cancer, let’s take a quick look at how the colon and rectum work:

• Digestive Process: After food is broken down in the stomach and small intestine, it moves to the colon, where water and nutrients are absorbed. The waste then travels to the rectum, where it’s stored until it’s time to go.

• The Colon and Rectum: Together, the colon and rectum make up the large intestine. The colon has four parts—ascending, transverse, descending, and sigmoid—that each play a role in forming poop. The rectum connects to the anus, where waste leaves the body.

• Cell Types: The lining of the colon and rectum contains various types of cells, including gland cells that produce mucus to help stool pass smoothly. Colorectal cancer usually starts in these gland cells, when they form abnormal growths (polyps) that may become cancerous if left unchecked.

Why Colorectal Cancer is Unique

Colorectal cancer stands out among other gastrointestinal (GI) cancers, like stomach or esophageal cancer, due to its high prevalence and the potential for prevention through regular screenings. Each year, more than 150,000 people in the U.S. are diagnosed, making colorectal cancer a top concern for public health.

Unlike anal cancer, which affects the very end of the digestive system, colorectal cancer impacts the parts of the intestine responsible for absorbing nutrients and water. Because colorectal cancer is common, it’s a major focus of cancer prevention, research, and screening programs.

Awareness and early detection are key, especially in communities facing barriers to healthcare. Screening tests like colonoscopies or stool-based tests can detect cancer early, when treatment is most effective. Taking proactive steps, like getting regular screenings, can make a big difference. Knowledge is power—and it’s the first step to prevention.