Colorectal Cancer

Colorectal cancer is caused by a growth that starts in the colon or rectum of the large intestine and may spread. The large intestine is part of the digestive tract.

A Painful Surprise

In October 1998, New York Yankees outfielder Darryl Strawberry had pain in his stomach and went to see his doctor. Surprisingly, the cause turned out to be colon cancer. Many people believe colon cancer affects only older people or only men, but anyone can get the disease. The American Cancer Society estimated that there would be more than 111,000 new cases of colorectal cancer diagnosed in 2015. Colorectal cancer is the second leading cause of cancer death, with 49,700 Americans expected to die from this disease in 2015. However, rates of death have been declining for 20 years. When discovered early, colorectal cancer is frequently curable, and most deaths could have been prevented by early screening and follow-up medical care. Colon cancer is not contagious.

What Is Colorectal Cancer?

The colon and rectum

Colorectal cancer begins in either the colon or the rectum. Both are part of the digestive tract, which consists of a series of tubes and organs that process food. Digestion begins in the stomach. From the stomach, partly digested food passes into the small intestine, the longest section of the digestive tract, which absorbs most of the nutrients. The food then continues into the large intestine (the colon), which is a muscular tube approximately five feet long. In the colon, the remaining water and nutrients are extracted from the food and the remaining matter is stored as waste. The waste moves from the colon into the rectum and then passes through the anus and out of the body during a bowel movement.

Polyps and adenocarcinoma

Colorectal cancer does not happen suddenly. It can take many years to develop, and it usually is preceded by changes in the lining of the colon or rectum that occur over several years. One of these changes is a growth of tissue into the center of the colon or rectum, called a polyp (POL-ip). Not all polyps develop into cancer; those that do are called neoplastic polyps, or neoplastic lesions. Removing a neoplastic polyp prevents it from later becoming cancerous. Moreover, not all colon cancer begins with polyps. In the case of hereditary nonpolyposis colon cancer, polyps do not form.

What Happens When People Have Colorectal Cancer?

Signs and symptoms

Darryl Strawberry had gnawing pains in his abdomen * , and these pains caused him to go to the doctor. Another symptom is a change in bowel habits, for example, diarrhea or constipation that lasts for more than a few days. Individuals might feel the need to have a bowel movement even after they have had one or they might notice bleeding from the rectum or blood in the stool. Some people, however, have no noticeable symptoms.


Colonoscopy is a procedure in which a long, flexible tube called a colonoscope is inserted into the patient's anus in order to view the lining of the colon and rectum.

Colonoscopy is a procedure in which a long, flexible tube called a colonoscope is inserted into the patient's anus in order to view the lining of the colon and rectum. It is performed to test for colorectal cancer and other bowel diseases and it enables the physician to collect tissue samples for laboratory analysis.
Illustration by Electronic Illustrators Group. © 2016 Cengage Learning®.

Just because people have symptoms does not mean that they have colorectal cancer. The only way to be sure is to have a medical examination. It also is possible for people to have colon or rectal cancer and not have any symptoms. Because older people are more likely to develop colorectal cancer, medical professionals recommend that all

How Is Colorectal Cancer Treated?

If cancer is found, the next step is to do tests to see whether it has spread. Doctors use a four-level system of numbers or letters to stage, or classify, the cancer. The lower the number or letter, the less the cancer has spread. A higher number, for example, stage IV, means a more serious stage of the disease.

The three main types of treatment for colorectal cancer are surgery, radiation therapy, and chemotherapy:

Can Colorectal Cancer Be Prevented?

People can take steps to reduce their risk and in many cases to prevent colorectal cancer from developing.

Screening and other precautions

Because finding colorectal cancer early often means it can be cured, people age 50 and older should follow the screening guidelines established by the American Cancer Society. Younger people whose close relatives (mother, father, sister, or brother) have had colorectal cancer or physical conditions that increase the risk for colorectal cancer should begin screening earlier than age 50. Younger people who have had colorectal cancer already must be particularly careful to follow up with their doctors regularly to make sure the cancer does not return.

Illustration showing the development of a cancerous tumor within the colon.

Illustration showing the development of a cancerous tumor within the colon.
Illustration by Argosy, Inc. © 2016 Cengage Learning®.

Eating a healthy diet, getting plenty of exercise, and never smoking or quitting if you do are other precautions people can take to decrease their risk.

What Is It Like to Live with Colorectal Cancer?

Caught in the early stages, colorectal cancer is one of the most curable cancers. People recover from surgery and resume their normal lives. Many people are embarrassed about having colorectal cancer, however, because it involves a part of the body they do not usually talk about. Moreover, people who have had permanent colostomies may feel different from everyone else and embarrassed by the colostomy bag. Every individual's reaction to cancer and to treatment is different. There is no single right way to handle it. Support groups can be particularly helpful for people who are living with this very curable form of cancer.

See also Cancer: Overview • Inflammatory Bowel Disease • Polyps • Tumor


Books and Articles

Larson, Carol Ann. Positive Options for Colorectal Cancer: Self-Help and Treatment. 2nd ed. Alameda, CA: Hunter House, 2014.

National Comprehensive Cancer Network. “Looking Back: 20 Years of Colorectal Cancer Treatment Breakthroughs Improve Survival, Advance Evidence-Based Choices.” . (accessed November 29, 2015).

National Comprehensive Cancer Network. NCCN Guidelines for Patients: Colon Cancer. Author, 2014.


American Cancer Society. “Colorectal Cancer.” (accessed November 29, 2015).


American Cancer Society. 250 Williams St. NW, Atlanta GA 303031034. Toll-free: 800-227-2345. Website: (accessed November 29, 2015).

* abdomen (AB-do-men), commonly called the belly, is the portion of the body between the thorax (THOR-aks) and the pelvis.

* colostomy (ko-LOS-to-mee) is a surgical procedure in which a part of the large intestine is removed, and the end of the intestine is attached to an opening made in the abdomen. The stool is passed through this opening into a special bag.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)