 |
| D. Kim Turgeon, M.D., F.A.C.P. |
Here are the facts: Colorectal cancer is the second leading
cause of cancer death in the United States, and the leading
cancer killer among non-smokers. In 2005, the American Cancer
Society estimates that over 145,000 new cases will be diagnosed
in the U.S., and over 56,000 men and women will die from colorectal
cancer. Michigan alone will account for more than 4,800 of
those estimated new cases and approximately 1,900 of those
deaths.
Yet one overwhelmingly hopeful fact stands in stark contrast
to these frightening statistics:The vast majority of colorectal
cancer deaths are preventable by screening and early detection.
If that's the case, why doesn't everyone take steps to be
screened for colon cancer? For an answer, Progress
turned to D. Kim Turgeon, M.D., F.A.C.P., clinical associate
professor in the Department of Internal Medicine at U-M to
provide some background on the disease, define who's at risk
and describe what's involved in screening.Turgeon did all
that and more: she also gave every Progress reader the chance
to take part in her latest prevention outreach initiative:
The Polyp Pest.
Colon Cancer's Causes
Colon cancer actually refers to cancer of the large intestine
or large bowel, which is made up of the colon and the rectum,
or colorectum. Science is still grappling with the exact causes
of the disease, but it is known that nearly all (95%) of colorectal
cancers begin as a particular type of polyp called an adenoma.
It is thought that mutations in specific genes eventually
cause normal cells in the lining of the colon to develop polyps.
Eventually, the accumulation of more mutations in specific
genes can turn these adenomas into cancers. Most polyps in
the colon are benign. Not all polyps are adenomas that can
turn cancerous. Identifying and removing polyps to prevent
the development of colorectal cancer is the purpose of a colonoscopy.
Risk Factors More than 90% of colon cancer cases occur in
people (men and women equally) age 50 and older, making age
the No. 1 risk factor for the disease. There are, however,
other risk factors to consider:
- Family history of colorectal cancer or adenomas
- Cigarette Smoking -- which can increase the risk of
colon cancer death by 30%-40%, perhaps accounting for
up to 12% of colon cancer fatalities
- Obesity
- Sedentary lifestyle
- High fat diet, especially one from mostly animal sources
- Heavy alcohol intake
- Ulcerative colitis or Crohn's colitis
- Cancer of the uterus or ovaries before age 50
- Past removal of the gallbladder
- Past radiation of the abdomen
- Diabetes-- increasing the risk of developing colorectal
cancer 30%-40%
Turgeon cautioned that the absence of these additional risk
factors is no excuse to avoid screening. "Very significant
risk develops because of age alone," she reminds us.
Symptoms
Symptoms of colon cancer include rectal bleeding, anemia,
a change in bowel habit, abdominal pain and weight loss. But
unfortunately, notes Turgeon, "these symptoms are common
and often do not signal colorectal cancer. Worse yet, when
they are caused by cancer, they often represent the disease
in its late stage."
 |
| Colonic Adenomas
(polyps), the “warty” growths on the inner lining of the
colon. Usually benign, they can turn cancerous. Polyps
can be removed during a screening colonoscopy. |
Screening
As Turgeon notes, this form of cancer nearly always develops
from adenomas in the colon and rectum. Screening tests can
find these polyps, making it possible to remove them before
they turn into cancer, as well as finding colorectal cancer
early, when survival rates are highest. "Colorectal cancer
has four stages," she explains. "Stage one cancers
are confined to the inner lining of the colon and first layer
underneath it.When these are found and removed, there is a
survival rate of more than 95%. Stage two tumors have spread
into or through the muscle layer of the colon but do not involve
the lymph nodes ¨C catching the cancer here results in an
80% survival rate. At stage three, tumors involve the lymph
nodes adjacent to the colon, and the survival rate decreases
to about 50%. At the final stage, the tumors have spread to
distant organs, most commonly to the liver, and the survival
rate is about 5%. Clearly, the ability to see and remove precancerous
polyps and cancerous tumors early is the key."
In fact,Turgeon considers one screening tool, the colonoscopy,
to be the most powerful prevention tool in clinical medicine,
since it can both identify and remove precancerous polyps.
Other colon cancer screening tools include the fecal (stool)
occult blood test with flexible sigmoidoscopy and the double
contrast barium enema.Together they comprise a powerful arsenal
in the war against colon cancer.
For people at average risk, current recommendations call
for screening to begin soon after one’s 50th birthday, then
continuing at regular intervals. Individuals should discuss
screening options with their physicians to determine whether
they fall into an elevated risk group requiring testing to
begin before age 50. The doctor and patient together can also
decide which test to pursue and when the test should be repeated.
“Currently, although awareness of colon cancer is increasing,
rates for screening remain below those of breast, cervical
and prostate cancer, even though the evidence is so strong
to support getting tested,” says Turgeon.Why? She believes
many adults, thinking they have no symptoms, don’t realize
they are at risk. “Once symptoms are present, it’s a whole
new situation. Half of those who are diagnosed after symptoms
have developed will die from this cancer.That’s why it’s so
important to be screened before symptoms show up.”
Of course, there are other barriers to overcome.“People are
uncomfortable discussing that part of the body, and they’re
also fearful of the test.” As Turgeon notes, for most patients,
the test itself is not difficult. Performed under conscious
sedation, it results in little if any pain. But the bowel
preparation necessary prior to the test can be quite uncomfortable,
requiring frequent trips to the bathroom.“That’s why we need
to work harder to address these concerns and help patients
take charge of their own health.”To do so,Turgeon and her
colleagues at the U-M Cancer Center have launched a unique
program to encourage people
to get a screening colonoscopy, and to persuade those they
care about to do the same.
The Polyp Pest
Turgeon’s team designed the Polyp Pest, a special
bathroom door hanger to put to use when preparing for a colonoscopy.
“We realized that when it comes to encouraging colon screening,
sometimes you just need to be a pest. Although it sounds crazy,”
explains Turgeon,“we have a serious purpose in mind. In addition
to providing people with a friendly reminder of the importance
of colorectal cancer screening for themselves, we also want
to give them something they can easily pass along, encouraging
someone else to get screened too.We’ve included a toll-free
phone number and web address hoping that everyone who receives
it will contact us and let us know – anonymously – whether
they were screened, and whether they passed along the Polyp
Pest.”
Over a six-month period, approximately 40,000 Polyp Pests
will be distributed. Their “paths” will be tracked over the
course of a year to determine whether information, paired
with a little friendly pestering, can make a difference.
To learn more about Colon Cancer, or for help finding a doctor
near you, call the Cancer AnswerLine at 800-865-1125 or visit
www.mcancer.org/polyp_pest.
return to top |