Monday, March 2, 2009
Colon Cancer Awareness & Prevention
Susan Briley, MD, colorectal surgeon
William J. Harb, MD, colorectal surgeon
News notes provided by webmd.com
March is COLON CANCER AWARENESS MONTH
What Is Colorectal Cancer?
In order to understand colon and rectal cancer, collectively known as colorectal cancer, it might first help to understand what parts of the body are affected and how they work.
The colon is a 6-foot long muscular tube connecting the small intestine to the rectum. The colon, which along with the rectum is called the large intestine, is a highly specialized organ that is responsible for processing waste so that emptying the bowels is easy and convenient. The colon removes water from the stool, and stores the solid stool. Once or twice a day it empties its contents into the rectum to begin the process of elimination.
The rectum is an 8-inch chamber that connects the colon to the anus. It is the rectum's job to receive stool from the colon, to let you know that there is stool to be evacuated, and to hold the stool until evacuation happens.
What Is Colorectal Cancer?
Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Cancers affecting either of these organs also may be called colorectal cancer.
Colorectal cancer occurs when some of the cells that line the colon or the rectum become abnormal and grow out of control. The abnormal growing cells create a tumor, which is the cancer.
Digestive Diseases: Colorectal Polyps and Cancer
Colorectal cancer is the third most common cancer and the second leading cause of cancer deaths among American men and women. These cancers arise from the lining of the large intestine, also known as the colon. Tumors may also arise from the lining of the very last part of the colon, called the rectum.
Unfortunately, most colorectal cancers are "silent" tumors. They grow slowly and often do not produce symptoms until they reach a large size. Fortunately, colorectal cancer is preventable, and curable, if detected early.
How Does Colorectal Cancer Develop?
Cancer of the colon and rectum usually begins as a polyp. The word "polyp" is a nonspecific term to describe a bump on the surface of the colon. Polyps can also be bumps of normal colorectal lining which do not increase the risk of colorectal cancer.
The two most common types of polyps found in the large intestine include:
Although most polyps never become cancerous, virtually all colon and rectal cancers start from these benign growths.
Polyps and colon cancer develop when there are mutations or errors in the genetic code that controls the growth and repair of the cells lining the colon. People may inherit diseases in which the risk of colon polyps and cancer is very high.
Who Is at Risk for Colorectal Cancer?
While anyone can get colorectal cancer, it is most common among people over the age of 50. Risk factors for colorectal cancer include:
What Are the Symptoms of Colorectal Cancer?
Unfortunately, colorectal cancer may strike without symptoms. For this reason, it is very important to be screened regularly by your doctor for colorectal cancer, even if you have no symptoms.
There are a number of tests your doctor can perform to diagnose colorectal cancer. These tests include:
The earliest sign of colon cancer may be bleeding. Often tumors bleed only small amounts intermittently, and evidence of the blood is found only during chemical testing of the stool. This is called occult bleeding, meaning it is not always visible to the naked eye. When tumors have grown to a large size they may cause a change in the frequency or the diameter of the stool.
Common symptoms of colorectal cancer include:
What Happens If a Polyp Is Found?
If polyps are found, they should be removed and sent to a laboratory for microscopic analysis. Once the microscopic type of polyp is determined, the follow-up interval for the next colonoscopy can be made.
How Is Colorectal Cancer Treated?
The majority of polyps can be removed during a routine colonoscopy and looked at and examined under a microscope. Very large adenomas and cancers are removed with surgery. If the cancer is found in the early stages, surgery is curative. Advanced colorectal cancers may be treated in a variety of ways, depending on their location. Treatments include surgery and radiation therapy or chemotherapy.
How Can I Prevent Colorectal Cancer?
Living a healthy lifestyle that includes regular exercise, maintenance of a healthy weight, and a diet that is low in fat and high in fiber, vegetables and fruit is probably your best start at general cancer prevention. Checking the colon for polyps and cancer is another important step.
General Screening Recommendations:
These recommendations are for people without symptoms or a personal or family history of colorectal polyps or cancer or inflammatory bowel disease. Screening should begin at the age of 50.
The recommendations for those at a higher risk of developing colon cancer are listed below.
Family history of colorectal cancer (this includes parents, siblings or children):
Begin screening (colonoscopy preferred) at the age of 40 or 10 years earlier than the youngest person in the family who was diagnosed with colon cancer. For example, if your parents or siblings were diagnosed with colon cancer at age 55, you should start screenings at age 45.
People with precancerous polyps (adenomas) of the colon (1-2, less than 1 cm, tubular adenomas):
People with large (1 cm or larger), more than 2 adenomas or adenomas with villous components or severe dysplasia:
People who have undergone surgery for colon cancer and have no remaining colorectal polyps:
People with a family history of familial adenomatous polyposis:
People with a family history of hereditary non-polyposis colon cancer:
People with inflammatory bowel disease: