How to detect colorectal cancer early

Colorectal cancer is the third most common form of cancer in men and women and the third leading cause of cancer deaths in Americans.  In 2010, approximately 142,570 patients are estimated to be diagnosed with this malignancy, of which 102,900 are of colonic and 39,670 of rectal origins.  An estimated 51,370 will die of this disease. 

Screening of asymptomatic patients with normal risk begins at age 50.  In general, physicians recommend doing ONE of the below:

1)  Colonoscopy every 10 years.  A gastroenterologist or surgical specialist performs this procedure, which takes about 20-30 minutes.  The patient can have sedatives administered through an IV (intravenous catheter).  The scope enters the anus, goes up the rectum, into the sigmoid, left colon, transverse colon, right colon and ends where the right colon joins the small intestine.  Anything that looks suspicious can be removed with graspers introduced through the scope. 

2) Flexible sigmoidoscopy every 5 years.  Here, the scope is shorter and the procedure faster, because it only reaches the sigmoid part of the colon.  This approach is acceptable because the majority of colon cancers occur within the rectum and sigmoid colon.

3)  Double-contrast barium enema every 5 years.  X-ray contrast is inserted into the colon with an enema, then multiple X-ray pictures are taken of the entire colorectum at different angles.  If any abnormality is discovered, then the patient would need to undergo a colonoscopy to take a direct look and biopsy the abnormality.

4)  Stool studies every year looking for a minute amount of blood that is not obviously visible to the eye.  Often, colon cancer erodes and bleeds slowly.  Usually, this approach is combined with either sigmoidoscopy or barium enema.  

Screening for high-risk patients can be much more frequent and/or start earlier.  High-risk conditions includes:

a)  Inflammatory bowel disease (ulcerative colitis or Crohn’s disease).

b)  Previous colorectal cancer or adenomatous polyps.

c)  A first-degree relative with colorectal cancer or adenomatous polyps:  screening should start at age 40 years or 10 years younger than the earliest diagnosis in the first-degree relative.

d)  Family history of hereditary colon cancer (familial adenomatous polyposis, hereditary non-polyposis colorectal cancer-HNPCC, MYH-associated polyposis):  screening may start as early as puberty.

Please keep in mind that the screening recommendations above apply to “asymptomatic” patients.  If you think that you have new symptoms, such as abdominal pain, constipation, blood in stool, etc, discuss with your doctor.  There are new screening methods such as virtual colonoscopy and DNA tests of the stool.  Most of these tests may not be covered by insurance at this time, since they do not yet have established data to show their effectiveness.