Sarah Cannon - February 02, 2019

March is Colorectal Cancer Awareness Month. Colorectal cancer is one of the most common cancers in the U.S. It is important to understand how colorectal cancer functions in the body and how it is diagnosed, so you can feel confident in your care if you or someone who know develops the disease.

Colorectal Cancer 101

90-95% of all colorectal cancers are adenocarcinomas. This is a cancer that begins in cells that make and secrete fluids such as mucus. These cells are found in glandular tissue.

The cancer generally starts from benign polyps called adenomas. Colon polyps are a common occurrence. In fact, 25% of people over age 50 have polyps. It is important to remove these polyps to ensure they do not become cancerous.  The bigger the adenoma is, the more likely it is to become cancerous.

Diagnosing Colorectal Cancer

If you are being examined for colorectal cancer, the first thing your doctor will do is review your medical history. He or she will conduct a thorough medical exam and then may conduct one or more of the following tests:

  • Digital Rectal Exam:This exam checks the rectum for lumps, bleeding, or other abnormalities. About half of colon cancers can be detected in this way.
  • Fecal Occult Blood Test:Blood in stool can be an indicator of colorectal cancer. Stool may also contain blood for other reasons not related to colorectal cancer. If you experience blood in your stool, contact your healthcare provider.
  • X-ray of the Large Intestine or Barium Enema:An X-ray provides a picture of the colon and can help identify any polyps.
  • Colonoscopy:A colonoscopy is used to examine the bowel's interior surface for abnormalities like polyps.
  • Biopsy:A biopsy allows the doctor to remove a small sample of tissue to then be sent to a pathologist for examination.
  • Virtual Colonoscopy:This is a type of CT scan. It uses computer software along with CT imaging to examine the colon for polyps.

Stages of Colorectal Cancer

  • Stage 0: This is an extremely early stage. Abnormal cells are found only in the superficial layer of the colon wall. Stage 0 is also called carcinoma in situ.
  • Stage 1: This is a very early stage. Cancerous cells have been found up to the muscular layer of the colon wall. However, it has not spread beyond the colon wall.
  • Stage 2: Cancer has spread through the muscle layer to the outermost layer of the colon wall and possibly into surrounding tissue. However, the cancer has not spread to the lymph nodes.
  • Stage 3: Cancer has spread to nearby lymph nodes but not to other parts of the body.
  • Stage 4: Cancer has spread beyond the colon to other parts of the body - most often the liver and lungs. This is a metastatic disease.

"Awareness and screening are key in the fight against colorectal cancer," said Douglas Srygley, MD, gastroenterologist at Sarah Cannon Cancer Institute at St. David's HealthCare in Austin, Texas. "Screening can detect polyps for removal and ultimately help prevent the development of colorectal cancer. The earlier colorectal cancer is found the better the long-term outcome for the patient."

Sarah Cannon recommends flexible sigmoidoscopy every 5 years or a colonoscopy every 10 years for those 45 years of age or older. Dependent on your risk, there are alternative tests that can be conducted. It is important to talk to your healthcare provider about the right course of action for you.

For more information on colorectal cancer diagnosis, treatment and survivorship, visit our colorectal cancer page.

If you have questions about colorectal cancer, call askSARAH at (844) 482-4812.

It is important to know that the information in this post, including Sarah Cannon’s recommendations for screening, is accurate as of the publishing date.