Colon Cancer

Colon cancer is cancer grows in the large bowel. Colon cancer ranks number 3 of cancer related deaths in the United States. The lifetime risk of developing colon cancer is about 1 in 20. The death rate from colon cancer has significantly decreased since the broad use of colonoscopy for colon cancer screening for more than 20 years. Most of the colon cancers begin as adenomatous polyps. There are several types of colon cancer, such as colon carcinoma, lymphoma, carcinoid tumors, melanoma, and sarcomas. Colon carcinoma is the most common type. Here, we mainly discuss about colon carcinoma.

Causes and Risk Factors

The most common ones are:

  • Older age
  • Race. African American and Eastern European decent have higher risk of colon cancer.
  • A personal history of colon cancer or colon polyps
  • Family history of colon cancer and colon polyps
  • Inherited disorders or syndromes
  • Crohn's disease
  • Ulcerative colitis
  • Low fiber diet
  • High fat diet
  • Inactive lifestyle
  • Diabetes
  • Obesity
  • Smoking
  • Alcohol
  • Radiation therapy for cancer

Symptoms and Sign

Colon cancer can happen without warnings or symptoms. The most common symptoms and signs are:

  • A change in your bowel habits
  • Thin stools
  • Rectal bleeding
  • Invisible blood in your stool
  • Anemia
  • Abdominal discomfort or pain
  • Nausea
  • Vomiting
  • Weakness
  • Fatigue
  • Low appetite
  • Weight loss

Diagnosis, Screening, and Treatment

Diagnosis is based clinical presentation and risk factors with one or more of the following tests:

  • Blood works
  • Stool studies
  • X-ray
  • Sigmoidoscopy
  • Colonoscopy
  • CT
  • EUS

Screening is recommended beginning at age of 50 years old for all, with some special groups at an earlier age. Screening colonoscopy has been proven to be an very effective method to prevent colon cancer. Other alternative methods are:

  • Flexsigmoidoscopy
  • Barium enema
  • Stool test for occult blood
  • CT colonography

Treatment is based on the pathology finding, spread of the tumor, the patient health status, etc. Earlier cancer within the lining of the large bowel maybe removed through Colonoscopy or Flexsigmoidoscopy. The common treatment modalities of colon colon are:

  • Chemotherapy
  • Radiation therapy
  • Surgery


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  2. Wikipedia.
  3. Mayo clinic online health information.
  4. Sleisenger and Fordtran's Gastrointestinal and Liver Disease- by Mark Feldman MD, et al.
  5. The Little Black Book of Gastroenterology-by David W. Hay.
  6. Principles of Clinical Gastroenterology by Tadataka Yamada, et al.