Transcript COLORECTAL POLYPS AND COLORECTAL CARCINOMA

COLONIC POLYPS
 May occur in any part of the colon
 Majority of them arise in the rectum and sigmoid
colon
 They tend to cause rectal bleeding (visible or
occult) and may undergo malignant change
 If rectal polyps are found, the entire colon must be
investigated- total colonoscopy
 The larger the lesion the more likely it is to be
malignant
COLORECTAL POLYPS
 Histopathologically- three patterns of growth:
 tubular adenomas
 villous adenomas
 tubulo-villous adenomas
PHYSICAL EXAMINATION
 General examination- features suggesting malignant
disease:
 Obvious weight loss
 Palor of the skin
 Abdominal distention
 Hepatomegaly
 Abdominal mass
PHYSICAL EXAMINATION
 Rectal examination:
 Finger can reach lesions as far as the its length 7-9 cm
 Palpable fixed mass in Douglas pouch-sigmoid tumor
dropped retrorectally
 The glove inspected for blood and mucus
Types of Colon Cancer
IBD
1%
Sporadic
80%
Familial
15%
Hereditary
4%
Risk Factors
Risk increases with age
Nearly 90% of colon cancer patients
are over the age of 50.
Other risk factors include:
family or personal history of colon cancer
or polyps
chronic inflammatory bowel disease
hereditary colorectal syndromes
use of cigarettes and other tobacco products
high-fat/low fiber diet
physical inactivity
Symptoms
Early colon cancer usually has no symptoms
Signs and symptoms typically occur only in advanced colon cancer.
Symptoms may include:
Change in bowel habits lasting more
than a few days
Bleeding from the rectum
Blood in the stool
Cramping or gnawing stomach pains
Weakness and fatigue
Jaundice (yellow-green color of the skin & white part of the eye)
Colon Cancer Tests
Get the test. Get the polyp. Get the cure.
 Fecal occult blood testing (FOBT)
 Barium enema
 Flexible sigmoidoscopy
 Colonoscopy
 Virtual Colonoscopy
Colonoscopy
Colonoscopy
Get the polyp. Get the cure.
Advantages
 Detects >90% polyps and
cancer
 Provides diagnosis and
therapy
 Medicare covers
average-risk
Limitations
 Risks
 Availability
 Cost
 Compliance
Are people getting tested?
Testing rates remain far too low
 Fewer than half of Americans over age 50 report having had a
recent colorectal cancer screening test
 Because of low testing rates, only 39% of colorectal cancers are
detected at the earliest, most treatable stage
Ethnic/Racial differences
 Percentage who have never had screening
colonoscopy
 Hispanics - 67%
 Black - 55.8%
 White, non-Hispanic – 47%
 Never married 60%
 Education less than high school diploma 58%
vs 52% completed high school vs 46% with
some college education
2005 data, AHRQ
Virtual Colonoscopy
Virtual Colonoscopy
 Spiral CT to generate 3D images
 Cleaning of bowel, distension with air
 Non invasive, no complications
 Not endorsed for CRC screening
Virtual Colonoscopy
Limitations Virtual Colonoscopy
 Variable results
 No screening studies
 No longitudinal studies
 Cost
 Does not allow for therapy
Stool DNA
 Now recommended by ACS and USMSTF for average
risk individuals
 Multi-target DNA stool assay required to achieve
adequate sensitivity and detect the various gene
mutations
21 separate point mutations
P53
DIA
APC
K-ras
BAT-26
Video Capsule Colonoscopy
 In the process of development
 Battery life
 No clinical data available
 Anticipate to see clinical trials
Colon Cancer Tests
Average Risk
Average Risk Individuals
No Symptoms
Age  50
No risk factors
Current Recommendations
Average Risk
Test
FOBT
Sigmoidoscopy
FOBT + Sigmoidoscopy
Colonoscopy
Barium enema
*Preferred strategy by ACG
Interval (years)
Yearly
Every 5
Yearly, every 5
Every 10*
Every 5
Approach to Colon Cancer Testing
Asymptomatic
Men and Women
Age < 50 yr
No family Hx
Age  50 yr
YES family Hx
No Screening
HNPCC or FAP
NO family Hx
Average Screening
2 or more first-degree or
1 first-degree < 60 yrs
Genetic Counseling
Colonoscopy every
5 yrs, starting age 40
1 first-degree
 60 yrs
Average-risk
screening,
starting age 40
The flat polyp
 Techniques to improve detection
 Narrow-band imaging
 Chromoendoscopy
 Endocytoscopy
Soitenko et al. JAMA
March 2008
Narrow Band Imaging
Left sided ulcerative colitis
Ulcerative colitis with extensive
pseudopolyps
FAMILIAL POLIPOSIS COLI
 It is a rare autosomal dominant disorder
 Multiple colorectal polyps
 Rectal bleeding/ change in bowel habit
 The treatment- colorectal removal with ileoanal
anastomosis, or panproctocolectomy with definitive
ileostomy
Peutz-Jeghers syndrome
 It is an autosomal dominant inherited disorder
characterized by intestinal hamartomatous polyps in
association with mucocutaneous melanocytic macules.
 Patients with Peutz-Jeghers syndrome (PJS) have a 15-fold
increased risk of developing intestinal cancer
compared with that of the general population.
 Such cancer locations includes gastrointestinal and
extraintestinal sites.