|
Did You Know That Most Cancers Can Be Linked To Nutrition Deficiency?
Click Here For The Latest In Proven Cancer Nutrition And Supplements!
By Donald E. Mansell, MD
Board Certified Gastroenterologist
153 Pearson Rd.
Paradise, CA 95969 USA
Phone 530-877-0400
Contents
What Are Polyps?
What About Colon Cancer?
Why Do polyps And Colon Cancer Occur?
How Quickly Do Polyps and Cancer Grow?
So In Summary Who Is At Increased Risk For Colon Cancer
Needing Colonoscopy?
What Are The Symptoms Of Colon Cancer?
How Can I Prevent Colon Polyps And Colon Cancer?
Diagnosis Of Colon Cancer
Fecal Occult Blood Testing ( FOBT )Flexible Sigmoidoscopy
Colonoscopy
Barium EnemaScreening for Colon Cancer.
What If I Have Been Diagnosed With Colon Cancer?
Staging Of Colon CancerDuke's Classification
Prognosis
How Is Colon Cancer Treated?Evaluation
References
CreditLinks
Home Page
About the authorWhat Are Polyps?
Polyps are growths which develop in the colon and other
parts of the body as well. They vary in size and appearance.
They may look like a wart when small and when they grow
they may appear like a cherry on a stem or fig. They are
important because they can with time turn into cancer. Sometimes
they can bleed causing anemia. A polyp is defined as a growth
that projects, often on a stalk, from the lining of the
intestine or rectum. Polyps of the colon and rectum are
almost always benign and usually produce no symptoms. They
may, however, cause painless rectal bleeding or bleeding
not apparent to the naked eye. There may be single or multiple
polyps. The incidence of polyps increases with age.
The cumulative risk of cancer developing in an unremoved
polyp is 2.5% at 5 years, 8% at 10 years, and 24% at 20
years after the diagnosis. The probability of any singular
polyp becoming cancerous is dependent on its gross appearance,
histologic features, and size. The relative risk of developing
colon cancer after polyps have been removed is 2.3 compared
to a relative risk of 8.0 for those who do not have the
polyps removed. Polyps greater than 1 centimeter have a
greater cancer risk associated with them than polyps under
1 centimeter. Polyps with atypia or dysplasia are also more
likely to progress on to colon cancer.
The risk of cancer is much higher in sessile villous adenomas
than in pedunculated tubular adenomas. Cancer is found in
40% of villous adenomas, as compared to 15% in tubular adenomas.
The good news is that 65% of adenomas are tubular, with
villous adenomas accounting for only 10% of adenomatous
polyps. It has been shown that the removal of polyps by
colonoscopy reduces the risk of getting colon cancer significantly.
What About Colon Cancer?
Don't panic! Colon cancer has an excellent cure rate. Colon
cancer is a very common cancer second only to lung cancer.
129,400 new cases of colorectal cancer are estimated for
1999 with 56,600 deaths from CRC. The strongest risk factor
for colon cancer is age. The (Current Statistics on CRC)incidence
rates rise from 10 per 100,000 at age 40-45 to 300 per 100,000
at age 75-80. The cumulative life time risk for the disease
is 1 in 20.
Men are more likely to develop Colon Cancer than women.
Black Americans are more likely than White Americans to
be diagnosed with colorectal cancer. Smokers, drinkers,
sedentary and obese persons are more likely to develop colon
cancer.
Why Do polyps and Colon Cancer Occur?
Both polyps as well as colon cancer occur much more frequently
in industrialized, western societies.
Diets low in fruits, vegetables, protein from vegetable
sources and roughage are associated with a higher incidence
of polyps. Persons smoking more than 20 cigarettes a day
are 250% more likely to have polyps as opposed to nonsmokers
who otherwise have the same risks. Persons who drink have
an 87% increased likelihood of having polyps compared to
nondrinkers and those who both smoke and drink are 400%
more likely to develop polyps compared to their peers who
neither smoke nor drink. There is increasing evidence that
diets high in calcium can reduce the risk of colorectal
cancer. An even more potent agent in preventing colon cancer
is the eating of vegetables. Apparently it isn't the fiber
but it is likely that phytochemicals in vegetables act to
prevent cancer. People who exercise daily are less likely
to develop colon cancer. Polyps tend to cluster in families
so that having a first degree relative ( sibling, parent
or child ) with colon polyps raises ones chances of having
polyps. The familial cancer syndromes such as Lynch Syndromes
I and II ( rare ) carry a high risk of the development of
colon and other cancers.
Family adenomatous polyposis or FAP, is a rare condition
characterized by thousands of adenomatous polyps throughout
the large bowel.
People with 1st degree relatives with inflammatory bowel
disease are at increased risk and those who have a first
degree relative with colon cancer have a fourfold increase
in risk over the general population and should be screened
earlier with colonoscopy and more often than the proposed
outline for screening suggested by the American Cancer Society.
There is an association of cancer risk with meat, fat or
protein consumption which appear to break down in the gut
into cancer causing compounds called carcinogens. A personal
history of ovarian, endometrial, or breast cancer also appear
to be risk factors.
How Quickly Do Polyps and Cancer Grow?
It may take five years or more for a polyp to reach a 1/2
inch ( 1 cm ) in diameter. It generally takes a 1/2 inch
polyp 5-10 years or more to turn into cancer. It will then
take around 5-10 years for the cancer to cause symptoms
by which time it is frequently too late.
So In Summary Who Is At Increased Risk For Colon Cancer
Needing Colonoscopy?
PERSONS WITH ONE OR MORE OF THE FOLLOWING ARE AT
RISK FOR COLON CANCER
Woman who have been diagnosed with breast or ovarian or
uterine cancer Persons with a sibling, parent or child with
colon cancer Persons who are passing frank blood in the
stool
Men with iron deficiency anemia Women after menopause with
iron deficiency anemia Persons found on screening exams
to have blood present in the stool
What are the Symptoms of Colon Cancer?
The reason that screening in asymptomatic individuals is
so important is that most persons who have colon cancer
have either no symptoms or very nonspecific symptoms until
the cancer has become advanced.
Right sided, ascending colon tumors often present with fatigue,
weakness, and anemia of iron deficiency of unknown origin.
These lesions can grow quit large without causing any obstructive
symptoms because stool in the ascending colon is relatively
liquid and can continue to pass through even significantly
narrowed lumens. Lesions of the ascending colon often project
into the lumen and ulcerate, causing chronic blood loss
resulting in symptoms of palpitations, possible angina pectoris,
as well as fatigue. Any adult presenting with chronic iron
deficiency of unknown origin should have a through visualization
of the entire bowel via colonoscopy.
Since stool in the left descending colon is more formed,
symptoms of obstruction are often the first presenting symptoms.
Such symptoms include changes in bowel habits ( constipation
and/or diarrhea ), crampy left lower quadrant pain and even
perforation. Barium enema X-rays of left sided lesions often
reveal characteristic annular, constricting lesions.
How Can I Prevent Colon Polyps and Colon Cancer?
The incidence of colon cancer is higher in active smokers
compared to those who have stopped smoking, hence smoking
cessation is important for those who wish to decrease their
likelihood of developing colon cancer. Aspirin taken daily
reduces not only the incidence of both colon polyps and
colon cancer but of cancer of the stomach and esophagus
as well. It is felt that one coated adult aspirin ( 325
mg ) daily is adequate for the purpose of preventing colon
cancer.
Aspirin interferes in prostaglandin metabolism and this
seems to be the mechanism for it preventing cancer as well
as cardiovascular disease. It must be remembered that aspirin
can cause GI upset, ulcers and bleeding among other things.
Dietary supplementation with 1500 mg of Calcium or more
a day is associated with a lower incidence of colon cancer.
Weight reduction may be helpful in reducing the risk for
colorectal cancer. Daily exercise reduces the likelihood
of developing colon cancer. Selenium and other antioxidants
may be in the future be found helpful in reducing colon
cancer risk. Tumeric, the spice which gives curry it's distinctive
yellow color, may also prevent colon cancer.
Diagnosis of Colon Cancer
The diagnosis of colon cancer depends on a variety of methods
including barium enema, sigmoidoscopy, colonoscopy and biopsy
once a mass is found.
Fecal Occult Blood Testing ( FOBT )
Other names include: Occult Blood Testing, Hemocculttm,
Hemoquant,tm Hemoccult Sensatm, Hemewipestm, etc.
This is a test that detects the presence of occult ( detectable
only by chemical means and not visible ) blood in the stool.
Such blood may arise from anywhere along the digestive tract
but is most likely to originate in the colon.
There are many ways to collect the samples. You can catch
the stool on Sarantm wrap that is loosely placed over the
toilet bowel and held in place by the toilet seat. Then
put the sample in the clean container supplied or on the
card which was given you. One test kit, Hemewipes tm, supplies
a special toilet tissue that you use to collect the sample,
then put the sample in a clean container. For children wearing
diapers, you can line the diaper with Sarantm wrap.
Laboratory procedures vary. In one type of test, a small
sample of the stool is placed on a special paper "card".
A drop or two of testing solution is applied to a positive
and negative control at the bottom of the card. A color
change ( often blue ) indicates the presence of blood in
the stool.
Do not consume red meat or fish ( contain non-human hemoglobin
) for 3 days as this can cause a false positive reading
for blood. Discontinue drugs and substances that can interfere
with the test such as: Vitamin C which can cause a false
negative reading; Horse radish, fresh broccoli, turnips,
cauliflower ( have vegatable peroxidase ) and colchicine
which can give a false positive reading; Anticoagulants,
Aspirin or arthritis medicine which can cause leakage of
blood into the intestinal tract; Oxidizing drugs such as
topical iodine, bromides, and boric acid, and reserpine
need to be stopped about three days before the test as they
can cause a false positive reading.
Flexible Sigmoidoscopy
Flexible sigmoidoscopy can reach as high as the descending
colon and can be done by a trained Primary Care Physician.
Sigmoidoscopy has been proven to reduce the incidence and
mortality of colon cancer through early detection. Flexible
sigmoidoscopy however, is not an adequate method of screening
in hereditary colon cancer as 2/3 of the lesions develop
proximal to the splenic flexure. In these cases colonoscopy
should be used.
Flexible Sigmoidoscopy ( Flex Sig ) is done without sedation
usually in the practitioner's office. Flexible sigmoidoscopy
can detect about 65%¬75% of polyps and 40%¬65% of
colorectal cancers. This test, for an investment of 3-5
minutes, can with little discomfort reduce the likelihood
of your developing colon cancer and if colon cancer is present
detecting it at an early, highly curable stage.
Colonoscopy
Colonoscopy remains the gold standard for visualization,
biopsy and removal of colonic polyps. The removal of all
polyps by colonoscopy has been demonstrated to reduce the
risk of colon cancer by 76 to 90 percent. In 1994 over 2,000,000
colonoscopies were performed in the US and over 650,000
of these underwent polypectomy.
Barium Enema
Enthusiasm for the double contrast barium enema has declined
in recent years in favor of colonoscopy, despite its lower
cost. The reason for this decrease in use as a diagnostic
tool lies in the reduced sensitivity of this test in detecting
polyps of less than 1 cm, in detecting polyps in areas where
a single lumen is not detectable ( i.e. sigmoid, rectosigmoid,
hepatic and splenic flexures ) and patient comfort and compliance
issues.
Despite these limitations, when a colonoscopy is not possible
the double contrast barium enema when combined with a flexible
sigmoidoscopy is an acceptable alternative, with the exception
of surveillance familial polyps, familial colon cancer and
inflammatory bowel disease, where attention to small details
of the colonic mucosa is required and the likelihood of
biopsy or polyp removal is high.
Screening for Colon Cancer
Current screening procedures suggested by the American cancer
society include annual digital rectal examination beginning
at age 40, annual fecal hemoccult screening starting at
age 50 and sigmoidoscopy every 3-5 years beginning at age
50 for symptomatic individuals having none of the high-risk
factors for colorectal carcinoma. For those with high risk
factors screening should be done more often and at an earlier
age depending on the risk factor involved.
It is evident that better screening methods are needed as
only 38% of colon cancers are localized at the time of diagnosis.
If polyps are found on Flexible Sigmoidoscopy or on a Barium
Enema, Colonoscopy will usually be performed to remove the
polyps and to make sure that there aren't any other undetected
polyps or cancer. Screening of patients by use of carcinoembryonic
antigen or CEA is not recommended because it generally rises
after the tumor is large and has spread. It is not specific
for colon cancer and it can rise without having a cancer
in smokers.
Distant metastases is one of the worst prognostic signs
as this places the patient in the most advanced staging
category. Cancers of the large bowel generally spread through
the lymphatics or through the portal venous system to the
liver. The liver is the most frequent visceral site of metastatic
dissemination and is the initial site of distant spread
in one-third of recurring colon cancers, with two-thirds
of patients having liver involvement at the time of death.
Other commonly involved sites for metastatic spread when
the liver is involved are lung and bone and brain. Rarely
are the lung, bone, or brain involved without liver involvement.
The median survival after the detection of distant metastases
range from 6 to 9 months ( with heavy liver involvement
) to 24 to 30 months ( with initially small liver nodules
). The work up to detect metastatic spread after a primary
colon tumor is diagnosed may include: liver function tests,
abdominal CT to evaluate intra-abdominal extra colonic involvement,
chest x-ray and/or chest CT for lung nodules, and a bone
scan when indicated by new onset of bony pain.
How Is Colon Cancer Treated?
The surgical resection of colon cancer with 3-5 cm disease
free margins and resection of the mesentery at the origin
of the blood supply, including primary lymphatic drainage
sites, is required treatment to attempt a cure of the disease.
Usually colostomy(where the colon is brought out through
the abdominal wall requiring the placement of a bag to drain
the stool) can be avoided unless the cancer is too low (
usually less than 5 cm from the anus ).
Cure can be achieved with surgery alone in a large number
of patients. When the cancer is detected at an earlier stage
( this is why screening is needed ) the cure rates are much
higher. Overall 75% of patients ( Duke's A and B1 ) are
cured by a primary resection and of the 25% of patients
who develop a recurrence, 20% of these will be cured by
a second resection.
Today, adjuvant therapy is standard for patients with stage
TNM 3 or Duke's B2 and C colon cancer. A combination of
5-FU ( 5-fluorouracil ) and levamisole is used in stage
TNM 3 or Duke's C over a duration of 1 year postoperatively
and is combined with radiation therapy for Duke's stage
B2 and TNM stage 4. Adjuvant therapy with 5-FU and Levamisole
have been shown to increase the overall survival in patients
with TNM stage 3 colon cancer, over those treated by surgery
alone, from 46% to 60% after 6.5 years.
REFERENCES
• Kaster S, Buckley S, Haseman T, et al. "Colonoscopy
and barium enema in the detection of colorectal cancer."
Gastrointest Endosc 1995; 41:379.
• Winawer SJ, Zauber
AG, Ho MN, et al. "Prevention of colorectal cancer
by colonoscopic polypectomy." N Engl J Med 1993;329:1977-1981.
• Grossman S, Milos ML, Tekawa IS, et al. "Colonoscopic
screening for persons with suspected risk factor for colon
cancer. I. Family history." Gastroenterology 1988;39:395-400.
• Grossman S, Milos ML, Tekawa IS, et al. "Colonoscopic
screening for persons with suspected risk factor for colon
cancer. II. Past history of colorectal neoplasms."
Gastroenterology 1989;96:299-306.
• O'Brien MJ, Winawer SJ, Zauber AG, et al. "The National
Polyp Study: Patient and polyp characteristics associated
with high-grade dysplasia in colorectal adenomas."
Gastroenterology 1990; 98:371-379.
• Shulman K, Schilsky RL: "Adjuvant Therapy of Colon
Cancer. Seminars in Oncology" 22:6: 600-610, 1995.
• Arthur HI M.D., Diane FJ M.D., Murphy GP M.D.: American
Cancer Society Textbook of Clinical Oncology 213-217 &
157-161, 1991.
• Marnett
LJ Ph.D.: "Aspirin and Related Nonsteroidal Anti-inflammatory."
• Ransohoff DF. "Colon cancer in ulcerative colitis."Gastroenterology
1988;94:1089-91.
• Desaint B, Legendre Cl, Florent CH. "Dysplasia and
cancer in ulcerative colitis." Hepatogastroenterology
1989;36:219-26.
• Levin B, Lennard-Jones J, Riddell RH, Sachar D, Winawer
SJ, and the "WHO Collaborating Centre for the Prevention
of Colorectal Cancer. Surveillance of patients with chronic
ulcerative colitis." Bull World Health Org 1991;69:121-6.
• Ekbom A, Helmick C, Zack M, Adami HO. "Increased
risk of large bowel cancer in Crohn's disease with colonic
involvement." Lancet 1990; 336:357-9.
• "Drugs as Chemopreventive Agents against Colon Cancer."
Preventive Medicine 24: 103-106, 1995.
• Winawer SJ, Zauber AG, GErdes H, et al. Risk of colorectal
cancer in the families of patients with adenomatous polyps.
N Engl J Med 1996;334:82-87.
• Kumar, Cotran, Robbins: "Basic Pathology Textbook."
509-517, 1971.
• Lynch HT, Smyrk TC, Watson PC, et al. "Genetics,
natural history, tumor spectrum and pathology of hereditary
nonpolyposis colorectal cancer: an updated review."
Gastroenterology 1993;104:1535-1549.
• Palmieri GM: "Calcium, Why and How Much? " Miner
Electolyte Metabolism 21: 236-241, 1995.
• Koutlas T: The Mont Reid Surgical Handbook 317-323, 1994.
• Levin B and Murphy GP. "Revision in American Cancer
Society Recommendations for the Early Detection of Colorectal
Cancer." Ca-A Cancer Journal for CLinitions. 1992;42:(5)296-299.
• St. John, DJB, McDermott FT, Hopper JL, et al. "Cancer
risk in relatives of patients with common colorectal cancer."
Ann Intern Med 1993;118:785-790.
• Lipkin M: "Strategies for Colon Cancer Prevention."
Annals New York Academy of Sciences 170-179, 1995.
• Haller DG: "An Overview of Adjuvant Therapy for Colorectal
Cancer. " European Journal of Cancer 31A: 1255-1263,
1995.
• Scott-Conner CEH M.D., Ph.D., F.A.C.S., Christie DW R.R.A.,
M.B.A.: "Cancer Staging Using The American Joint Committee
on Cancer."
• "TNM System." Journal of the American College
of Surgeons 181: 182-188, 1995.
• American Cancer Society: "CA, A Cancer Journal for
Clinicians", Cancer Statistics 1995 45: 1, 1995.
• AT-A-GLANCE: "Colorectal Cancer: The Importance of
Early Detection":1996.
• Isselbacher, Braunwald, Wilson, et al: "Harrison's
Principles of Internal Medicine" 257: 1424-1429, 1994.
• Deans GT, Heatley M, Anderson N: "Jass' Classification
Revisited." Journal of the American Collage of Surgeons
179: 11-16, 1994.
• Potter JD: "Risk Factors for Colon Neoplasia-Epidemiology
and Biology." European Jouranal of Cancer 31A: 1033-1038,
1995.
• Toribara NW, Sleisenger MH: "Screening for Colorectal
Cancer." The New England Journal of Medicine 332:13:
861-865, 1995.
• Willett W: Who Is Susceptible to Cancers of the Breast,
Colon, and Prostate.
• Otchy DP "Aggressive surveillance, or colonoscopy
every three to five years, is warranted in persons found
to have one large colon polyp." Am J Gastroenterol
1996;91:448-454
• J. Erhardt, B. Siegle, U. Winzig, L. Diefenbach, C. Behrend,
A. Aldinger, J.C. Bode, C. Bode, Robert-Bosch-Krankenhaus
Stuttgart and University of Hohenheim, Department of Nutritional
Physiology, Germany"Alcohol consumption and nutrition
as a risk factor to develop colorectal neoplasia"
• Stellman SD: Aspirin and Cancer:
Report on an American Health Foundation Workshop.
Preventive Medicine 24: 101-102, 1995.
• Murakami R, et al Natural history of colorectal polyps
and the effect of polypectomy on occurrence of subsequent
cancer. Int. J. Cancer. 46:159, 1990
• Kronborg, O., et al. Follow-up after colorectal polypectomy.
II. Repeated examinations of the colon every 6 months after
removal of sessile adenomas and adenomas with the highest
degree of dysplasia. Scan. J. Gastroenterol. 18:1095, 1983.
• Kirsner, J.B., et al. Polyps of the colon and rectum:
Statistical analysis of a long term follow-up study. Gastroenterology
39:178, 1960.
• Stryker, S.J., et al. Natural history of untreated colonic
polyps. Gastroenterology. Jpn. 19:550, 1984.
• Schwartz AG; Pashko LL. Cancer chemoprevention with the
adrenocortical steroid dehydroepiandrosterone and structural
analogs. J Cell Biochem Suppl 1993;17G:73-9. Cancer Research
1995
• Policy and Procedure Manual for Gastrointestinal Endoscopy:
Guidelines for Training and Practice. ASGE. 1990.
http://personalweb.sunset.net/
~mansell/polyp.htm
| 
High Grade Liquid
Discount Brand Name
Vitamins And
Cancer Nutrition Packages!
ORDER NOW!
LOWEST PRICES
ONLINE ON ALL LIQUID
SUPPLEMENTS GUARANTEED!Only at www.SharpWebLabs.com!
Put Some Nutrition
In Your Life Today!
Guaranteed Satisfaction! Thousands Of Customers! Cancer And Nutrition Go Hand In Hand!
|
