Colorectal cancer (CRC) is the term referring to both rectal and colon cancers.

The colon (also known as the large intestine) is about five to six feet long, beginning at the cecum and ending with the anus.

The last five to ten inches of the colon is called the rectum.

Cancer located in the rectum is called rectal cancer, and cancer located in the rest of the colon is colon cancer. Some people also refer to colon and rectal cancers as bowel cancer.


Colorectal Cancer Definition

Colorectal cancer occurs when abnormal cells form tumors in normal tissues of the intestines and digestive system.

The exact type of “colon” or “rectal” cancer depends on where the abnormal cells first began and how fast they grew and spread. The main differentiator between these two cancers is where the tumor first forms — in the rectum or in the rest of the colon.

CRC may not show any symptoms at first, but as the tumor grows, it can disrupt your body’s ability to digest food and remove waste.

This causes potentially severe bowel and abdominal problems.

Polyps and How They Grow

A colon polyp is a small growth found on the inside of the colon.

Most colon polyps grow on the end of a stalk, somewhat like a mushroom. Although, some polyps, known as sessile polyps, can lie flat against the wall of the colon.

When it comes to polyps, you’re better safe than sorry.

When a polyp gets larger than the eraser on the end of a pencil (five millimeters) its cells can gradually become cancerous. Not all polyps will become cancer, but it is important to remove them all to block the possibility.

Image courtesy of Johns Hopkins Digestive Disorders Library

Colorectal Cancer Stages

Colorectal cancer is generally classified into the following four stages:

  • Stage I – A cancerous tumor forms in the colon or rectum
  • Stage II – The tumor has grown and possibly spread to nearby tissues
  • Stage III – Cancer cells spread to the lymph nodes
  • Stage IV – Cancerous tumors form in other body parts

At first, the tumor is contained within the colon or rectum. This is called “local” CRC. Over time, cancerous cells may move to nearby lymph nodes, and then to other parts of the body.

Late-stage colorectal cancer (stage IV or recurrent) means the cancer is advanced and the cancer cells have spread (metastasized) to form tumors in other areas of the body, such as the liver or lungs.

This is sometimes referred to as metastatic colorectal cancer.

Treating Colorectal Cancer

Deciding how to treat colorectal cancer relies heavily on knowing all of your treatment options. We have resources to help you out!

These expert recommendations for colon cancer treatment are based on current evidence.

  • The National Comprehensive Cancer Network’s Treatment Guidelines for Patients. It provides options for treatment at each stage and decision trees to help patients and their doctors decide which option to pursue.
  • Our Guide in the Fight is a comprehensive treatment guide that’s especially helpful for stage III and stage IV patients.
  • My Colon Cancer Coach can help you put together a personalized treatment plan.

Colon and Rectal Cancers Can Be Prevented

Did you know colon and rectal cancer can be prevented? Get screened.

Why? Here’s Rose’s story:

colon and rectum
Image courtesy of Johns Hopkins Digestive Disorders Library


By finding and removing precancerous polyps (adenomas) that can develop into cancer, colorectal cancer can be stopped before it ever starts.

Plus, screening for colon cancer can detect colorectal cancer early and when it’s most curable.

Get Screened

All average-risk adults age 45 should talk to their doctors about colorectal cancer screening. Adults who have a high risk of CRC should talk to their doctors about getting screened earlier.

There are plenty of screening options available, including at-home tests.

Some people have a greater-than-average risk and should work with their doctor to decide on a screening plan that works for them.

Screening can also find dangerous lesions that are not polyps.

Nonpolypoid colorectal neoplasms (NP-CRNs) are flat lesions in the colon that can be missed unless doctors look carefully for them, often using special colonoscopy techniques.

One cancer research study found them in almost ten percent of patients who had a colonoscopy.

While screening is the most important way to prevent colorectal cancer, there are also lifestyle changes that can reduce your risk for polyps and colorectal cancer.

Anyone Can Get Colorectal Cancer

While over 90 percent of colon and rectal cancers are found in people over the age of 50, anyone at any age can get colorectal cancer.

People younger than 45 need to protect themselves by knowing their family cancer history, as well as their own medical history.

People with a family history of certain cancer or with certain medical conditions may need to begin colonoscopy screening earlier and be tested more often.

In addition, everyone, no matter how old you are, needs to know the signs & symptoms of colorectal cancer and have a complete colonoscopy to rule out cancer if you have these symptoms.

Get Screened for Colorectal Cancer

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