Colon Cancer

Colon cancer is a serious disease that occurs when cancerous cells originate in the tissues of the colon. There are usually no early signs of the disease. When symptoms of colon cancer do appear, they can include bowel problems such as blood in the stool, narrow stools, and diarrhea or constipation. Some tests used to diagnose the cancer include rectal exams, fecal occult blood tests (FOBT), and colonoscopies. A few treatment options include surgery, chemotherapy, radiation therapy, or a combination of treatments.

 

Colon Cancer: An Introduction

Colon cancer is a disease in which malignant (cancer) cells first form in the tissues of the colon.
 

Colon Cancer and the Colon

The colon is part of the digestive system, which consists of the esophagus, stomach, small intestine, and colon (large intestine). The digestive system's main job is to pass waste out of the body while removing and processing nutrients from the foods you eat. These nutrients include:
 
  • Vitamins
  • Minerals
  • Carbohydrates
  • Fats
  • Proteins
  • Water.
     
The first six feet of the large intestine are called the large bowel or colon. The last six inches are the rectum and the anal canal. The anal canal ends at the anus (the opening of the large intestine to the outside of the body).
 
The colon removes water from your stool and helps pass waste material out of the body.
 

Colon Cancer Risk Factors

People 50 years old or older have an increased risk of developing colon cancer. Other colon cancer risk factors include having:
 
  • A family history of colon or rectal cancer
  • A personal history of the following cancers:

 

 

  • A history of colon polyps
  • A history of ulcerative colitis (ulcers in the lining of the large intestine) or Crohn's disease
  • Certain hereditary conditions, such as familial adenomatous polyposis and hereditary nonpolyposis colon cancer (also known as HNPCC or Lynch Syndrome).

 

(Click Risk Factors for Colon Cancer for more information.)

 

Symptoms of Colon Cancer

Like most cancer, colon cancer has no early symptoms. Once colon cancer symptoms appear, they may include the following:
 
  • A change in bowel habits
  • Blood (either bright red or very dark) in the stool
  • Diarrhea, constipation, or feeling that the bowel does not empty completely
  • Stools that are narrower than usual
  • Frequent gas pains, bloating, fullness, or cramps
  • Weight loss for no apparent reason
  • Feeling very tired
  • Vomiting.
     
Other conditions may cause the same symptoms, so it is important to see your healthcare provider if you experience any of these symptoms.
 

Diagnosing Colon Cancer

To make a colon cancer diagnosis, your doctor may perform one or more tests to look for the disease. These are the same tests used for colon cancer screening. They can include:
 

Staging Colon Cancer

If a biopsy shows that cancer is present, the doctor needs to know the stage of the colon cancer (how far it has progressed) to plan the best treatment. Colon cancer stages are based on whether the tumor has invaded nearby tissues, whether the cancer has spread, and, if so, to what parts of the body.
 
The different colon cancer stages include:
 
  • Stage 0
  • Stage I
  • Stage II
  • Stage III
  • Stage IV
  • Recurrent colon cancer.
     

Treatment for Colon Cancer

People with colon cancer have many treatment options available to them. These colon cancer treatment options include:
 
Many people receive more than one type of treatment for colon cancer, and the choice of treatment depends mainly on the stage of colon cancer. Your doctor can describe your colon cancer treatments and the expected results of each. You and your doctor can work together to develop a treatment plan that meets your medical needs and personal values. Choosing the most appropriate colon cancer treatment is a decision that ideally involves the patient, family, and healthcare team.
 
(Click Colon Cancer Treatment by Stage for more information on specific treatments for each stage of colon cancer.)
 

Colon Cancer Prognosis

Many factors affect a person's colon cancer prognosis. Some of the most important factors are the type and location of the colon cancer and the stage of the disease (the extent to which the cancer has metastasized, or spread).
 
Other factors that may also affect the prognosis include the person's:
 
  • Age
  • General health
  • Response to treatment.
     
(Click Colon Cancer Prognosis for more information.)
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Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD