What is colorectal cancer?

Colorectal cancer is a type of cancer that happens when cells of the colon or rectum divide uncontrollably. This usually begins as polyps, which are small growths of tissue in the the colon. Most of them are not cancerous, but some may grow out of control and become cancerous.

More specifically, most cases of colorectal cancer begin in the mucus-producing gland cells that line the intestine. These gland cells can be found in polyps. While there are other types of colon cancers, they are rare and treated differently.

Most precancerous polyps produce few, if any, symptoms. Because of this, it is crucial to get screened routinely for colon cancer. These screenings allow your doctor to find and remove polyps before they turn into cancer. Learn more about colon cancer screening.

Types of colorectal cancer

Most colorectal cancers begin as adenomas, which are a type of polyp that may become cancer.

Symptoms

Many people with colorectal cancer do not have symptoms in the early stages. As the disease advances, more symptoms may appear.

Symptoms may include:

• Diarrhea or constipation that does not go away
• Change in normal bowel habits, such as size, shape, and frequency
• Discomfort or urge to have a bowel movement when there is no need
• Cramping pain in your lower stomach
• Bloating or full feeling
• Change in appetite
• Bleeding from the rectum
• Blood in the stool or toilet after a bowel movement
• More exhaustion than normal
• Weight loss without dieting

In the later stages of colon cancer, polyps may spread (metastasize) to other parts of the body. This can cause other symptoms, depending on where cancer has spread.

These symptoms usually do not mean you have colorectal cancer. But, any time you notice unexplained changes and they continue for more than two weeks, do not assume they will just go away. See your doctor.

Risk factors

Anything that raises your chance of getting colorectal cancer is a risk factor.

Risk factors include:

• Age: Colorectal cancer is most often diagnosed in people aged 65-74. 
  • The median age is 67 years old
• Race: African Americans have the highest rate of colon cancer among all races in the United States.
  
• Family history of colon cancer, rectal cancer, or polyps
• Personal history of inflammatory bowel disease
  
• Past history of colorectal cancer or polyps
• Inherited  cancer syndromes: Some genetic changes can be inherited and increase your risk for certain types of cancer. Some inherited syndromes are Lynch syndrome (hereditary nonpolyposis colorectal cancer, or HNPCC) and familial adenomatous polyposis (FAP). These may put you at higher risk for developing colon cancer.

We offer genetic testing and counseling to help understand your risk.

Lifestyle choices that increase your risk include:

• Obesity
• Lack of exercise
• Diet: If you eat a lot of red meat, processed meats, or meats cooked at very high heat, you may be at a higher risk
• A lifestyle with large amounts of sitting
• Cigarette smoking
• Drinking too much alcohol

Prevention

Lifestyle choices that may decrease your risk of getting colon cancer include:

• Regular screening tests
• Staying at a healthy weight
• Regular exercise
• Eating a healthy diet with lots of fruits and vegetables
• Avoiding cigarette smoking
• Drinking alcohol only in moderation

Learn about ways to manage your colorectal cancer risk 

Related: Colorectal cancer prevention: What you need to know

Learn more about colorectal cancer:

• Colorectal cancer symptoms
• Colorectal cancer diagnosis
• Colorectal cancer treatment

Why choose MD Anderson for your colorectal cancer treatment?

At MD Anderson's Colorectal Center, your colorectal cancer treatment is personalized to provide the best outcomes, while focusing on your quality of life. We offer leading-edge treatments for colorectal cancer, including advanced minimally invasive surgeries that provide successful treatment with less impact on you.

MD Anderson is also uniquely experienced in sphincter-preserving surgeries, eliminating the need for a colostomy. 

Multidisciplinary Team Approach

Colorectal cancer treatment at MD Anderson is provided by a team of experts, including medical oncologists, surgeons, radiation oncologists, gastroenterologists, radiologists, clinical nurses, and mid-level providers, working in concert, to optimize your care. They discuss your case and develop a treatment designed to attack your cancer while minimizing side effects. 

Supplementing your clinical care, MD Anderson teams also provide assistance with nutrition, pain management, psychological support, wound management and other ancillary needs, in a holistic approach that treats not only your cancer, but you as an individual. 

In addition, our advanced knowledge in cancer genetics can help diagnose and treat inherited family syndromes that may increase your risk of colorectal cancer. This expertise also helps us work with you to plan the most effective treatment for your specific condition.

Leading-Edge Advancements

As one of the world’s largest cancer research centers, MD Anderson is a leading center for the investigation into new methods of colorectal cancer treatment and diagnosis. Through our clinical trials, this research can give patients access to treatments and procedures not found anywhere else.