Colon Cancer
by Yael Rosenberg, RN

   •  Description
   •  Symptoms
   •  Incidence and Carriers
   •  Treatment
   •  Testing
   •  Resources and More

Description
Colon cancer affects the colon which is the lowest part of the of the digestive system. It usually start out with polyps (which are benign growths) found on the lining of the colon, When these growths start growing at a rapid rate they become malignant and cancerous.

Risk Factors
   •  Age — Most colon and rectal cancers, also called colorectal cancer, develop in people age 40 and older, and risk increases with advancing age
   •  Family history — Close relatives of a person who has had colon or rectal cancer have a higher-than-average risk of developing the disease. In cases where many relatives have had it, known as familial colorectal cancer, the risk is even greater
   •  Polyps — Many colorectal cancers develop from polyps which are multiple, small, tumor-like growths in the colon A non-cancerous polyp may become cancerous over time, which makes removal an important step in prevention. Familial Polyposis is an inherited condition that leads to the development of many polyps in the colon and rectum. Inflammatory Bowel Diseases, such as chronic ulcerative colitis and Crohn's disease
   •  Ulcerative Colitis —These conditions cause inflammation of the lining and wall of the bowel. Scientists believe that colorectal cancer may result from cell overgrowth when new cells are generated to replace the diseased tissue
   •  Diet — A diet high in fat and low in fruits, vegetables, and high-fiber foods such as whole grain breads and cereals, has been linked to increased risk of colorectal cancer. In most studies, the food most strongly linked to increased risk of colon cancer was red meat.

Symptoms
   •  Any change in bowel habits
   •  Diarrhea, constipation, or feeling that the bowel does not empty completely
   •  Blood (either bright red or very dark) in the stool (often seen as coffee ground)
   •  Stools that are narrower than usual often stringy
   •  General abdominal discomfort (frequent gas pains, bloating, fullness, and/or cramps)
   •  Weight loss with no known reason
   •  Constant tiredness
   •  Vomiting

Incidence and Carriers
A gene linked to colon cancer has been reported in approximately 6% of Ashkenazi Jews. Approximately 500,000 Ashkenazi Jews may have mutations in this gene. A majority of these mutations occur at a single location in those Ashkenazi Jews carrying this gene.

A mutation in the APC gene places one at increased risk of developing colon cancer, and some have suggested that Ashkenazi Jewish patients with a familial history of colon cancer be tested for this specific mutation.

Ashkenazi Jews with these cancers and a history of these cancers can be tested to determine if a gene change is responsible and if that gene change can be identified. If a family's gene change is identified, other family members can have the test to determine whether or not they have inherited the gene change for increased susceptibility.

The gene test requires a sample of blood. Results are available within one to two weeks and the cost of thetest is around $200. When such a test is positive, regular colonoscopic examination, usually from age 35 onward, is imperative.

Treatment
Colon Surgery
The main treatment for colon cancer is surgery, in which the cancer and a length of normal tissue on either side of the cancer are removed, as well as the nearby lymph nodes.

Radiation Therapy
Radiation therapy is the use of high energy radiation to kill cancer cells either after surgery, to kill small areas of cancer that may not be seen during surgery, or instead of surgery. There are two ways to deliver radiation therapy:
   •  External beam radiation uses radiation from outside the body, which is focused on the cancer.
   •  Internal radiation therapy uses small pellets of radioactive material placed directly into the cancer.

Chemotherapy
Drugs (medications) are given into a vein or by mouth to kill cancer cells throughout the body. Studies have shown that chemotherapy after surgery can increase the survival rate for patients with some stages of colon cancer. Chemotherapy can also help relieve symptoms of advanced cancer.

Tumor vaccines
Tumor vaccines, now in clinical trials for colorectal cancer, are an attempt to re-educate the body to attack tumor cells. For reasons still unknown, at some point the body stops attacking cancer cells, even though evidence suggests that it does mount an immune attack against cancer cells when they are still small and few in number.

Stem cell support
Use of stem cell support in conjunction with chemotherapy for colorectal cancer is in clinical trials. Stem cells are very young blood cells that can repopulate depleted bone marrow. Reintroducing stem cells to the body after high-dose treatment permits very high doses of chemotherapy or radiotherapy to be used (since doses high enough to kill all cancer also destroy bone marrow).

Testing
Diagnosis
   •  Fecal Occult Blood Test - is a test used to detect small amount of bleeding in the stool.
   •  Sigmoidoscopy - is an examination of the rectum and lower colon (sigmoid colon) using a lighted instrument or scope.
   •  Colonoscopy - is an examination of the rectum and entire colon using a lighted instrument or scope.
   •  Double Contrast Barium Enema - patient is given an enema with a solution that contains barium, which outlines the colon and rectum on the x-rays.
   •  Digital Rectal Exam - is an exam in which the doctor inserts a lubricated, gloved finger into the rectum to feel for abnormal areas
   •  biopsy
   •  CEA assay - measures a protein called carcinoembryonic antigen, which is sometimes higher in patients who have colorectal cancer.

Screening Recommendations
The AHCPR panel recommended that, beginning at age fifty, persons at average risk for colorectal cancer undergo one of the following screening regimens:
   •  Fecal occult blood testing annually
   •  Flexible sigmoidoscopy every five years.
   •  Fecal occult blood testing annually and flexible sigmoidoscopy every five years.
   •  Double-contrast barium enema every five to 10 years
   •  Colonoscopy every 10 years.

Resources and More
     Colon Cancer Alliance, Inc.
     175 Ninth Avenue
     New York, NY 10011
     Office: 212-627-7451
     Toll Free Help-line: 1-877-422-2030
     Fax: 425-940-6147
     Website: http://www.ccalliance.org/

     American Society of Colon & Rectal Surgeons
     Telephone: 847-290-9184
     Fax: 847-290-9203
     85 W. Algonquin Road, Suite 550
     Arlington Heights, IL 60005
     Website: http://www.fascrs.org
     Email: ascrs@fascrs.org

This society offers a variety of brochures including several on colonoscopy and colorectal cancer. They can also provide listings of colorectal surgeons in your area.

     Colon Cancer Discussion List
     Association of Cancer Online Resources
     173 Duane Street, 3rd Floor
     New York, NY 10013-3334
     Website: http://www.acor.org/colon.html
The Colon Cancer Discussion List is provided by Association of Cancer Online Resources, Inc. (ACOR), a non-profit organization that provides information and support to cancer patients and those who care for them through the creation and maintenance of cancer related Internet mailing lists and Web-based resources. On the Colon Cancer Discussion list about 600 people regularly answer questions, exchange information and provide support to those dealing with colorectal cancer.