March's "Doctor On Call" Article: Colon Cancer
Colon Cancer is the second leading cause of cancer deaths in the United
States. The most recent data collected shows that in the year 2004, 146,940
people were diagnosed with the disease and 56,730 people died of it. The
mean age for detection is 68-70 and it is less likely below the age of
50. New cases and mortality have been decreasing since 1985, possibly
owing to increased screening.
Strong risk factors for the development of colon cancer include increasing
age, family history of colon cancer and inflammatory bowel disease (Crohn’s
disease and Ulcerative Colitis). Moderate risk factors are high consumption
of red meat, personal history of a certain type of colon polyps called
adenomatous polyps which are precursors to colon cancer, pelvic irradiation,
or a prior colon cancer. Modest risk factors include high fat low fiber
diet, alcohol, tobacco and obesity. Protective factors include aspirin,
non-steroidal anti-inflammatory drugs like ibuprofen, high physical activity,
fruits, vegetables, folate and calcium.
Symptoms of colon cancer are often absent for long periods of time and
many cancers are not detected until they have spread throughout the body,
which makes screening such an effective tool. Cancers can present with
rectal bleeding, a change in your bowel habits such as new onset diarrhea
or constipation, poor appetite, weight loss, and/or anemia.
Screening is the search for cancer and precancerous (adenomatous) polyps
in people without symptoms. It is very effective in colon cancer because
polyp removal can prevent the disease. In addition, cancers are slow growing;
therefore, early identification can result in surgical cure. Unfortunately,
screening is underutilized and 44 percent of people are never tested.
More than one screening method is available with certain advantages and
disadvantages of each. Fecal occult blood testing examines stool samples
for “hidden” blood. It is the most common, easiest and least
expensive method, but is only 30 percent effective. While important, it
needs to be combined with other tests below. Flexible sigmoidoscopy examines
the lower third of the colon through direst visualization via a rubber
tube with a light on the end of it. It is quite accurate, but cancers
or polyps in the upper 2/3 of the colon are missed. Barium enema examines
the entire colon by examining a radioopaque enema with an X-Ray machine.
However, since it is not direct visualization, it misses 50 percent of
small polyps and 25 percent of cancers. Colonoscopy, the most reliable
method, directly visualizes the entire colon and offers the capacity to
remove many growths and cancers during the examination; therefore, it
can cure as well as diagnose. It is a more expensive method, however,
and while very safe, does have a small risk of injury to the colon. Virtual
colonoscopy, “the new kid on the block,” uses a CT scanner
to examine the colon but is not currently endorsed by any national organization
If you are over the age of 50 or have family members with colon cancer
or colon polyps, you should get screened. Prevention is simple: Call and
schedule your screening today with Dr. Lee Klepper or Dr. Jonathan Bell
at Atlantic Gastroenterology, 410-629-1450.