COLONIC POLYPSMay occur in any part of the colonMajority of them arise in the rectum and sigmoid colonThey tend to cause rectal bleeding (visible or occult) and may undergo malignant changeIf rectal polyps are found, the entire colon must be investigated- total colonoscopyThe larger the lesion the more likely it is to be malignant
COLORECTAL POLYPSHistopathologically- three patterns of growth:
PHYSICAL EXAMINATIONGeneral examination- features suggesting malignant disease:Obvious weight lossPalor of the skinAbdominal distentionHepatomegalyAbdominal mass
PHYSICAL EXAMINATIONRectal examination:Finger can reach lesions as far as the its length 7-9 cmPalpable fixed mass in Douglas pouch-sigmoid tumor dropped retrorectallyThe glove inspected for blood and mucus
Types of Colon Cancer
Risk FactorsNearly 90% of colon cancer patientsare 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
Risk increases with age
SymptomsSigns 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) Early colon cancer usually has no symptoms
Colon Cancer TestsFecal occult blood testing (FOBT)Barium enemaFlexible sigmoidoscopyColonoscopyVirtual Colonoscopy
Get the test. Get the polyp. Get the cure.
ColonoscopyAdvantagesDetects >90% polyps and cancerProvides diagnosis and therapyMedicare covers average-risk LimitationsRisksAvailabilityCostCompliance
Get the polyp. Get the cure.
Testing rates remain far too lowAre people getting tested?Fewer than half of Americans over age 50 report having had a recent colorectal cancer screening testBecause of low testing rates, only 39% of colorectal cancers are detected at the earliest, most treatable stage
Ethnic/Racial differencesPercentage who have never had screening colonoscopyHispanics - 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 education2005 data, AHRQ
Virtual ColonoscopySpiral CT to generate 3D imagesCleaning of bowel, distension with airNon invasive, no complicationsNot endorsed for CRC screening
Limitations Virtual Colonoscopy
Variable resultsNo screening studiesNo longitudinal studiesCostDoes not allow for therapy
Stool DNANow recommended by ACS and USMSTF for average risk individualsMulti-target DNA stool assay required to achieve adequate sensitivity and detect the various gene mutations
K-rasAPCP53BAT-2621 separate point mutationsDIA
Video Capsule ColonoscopyIn the process of developmentBattery lifeNo clinical data availableAnticipate to see clinical trials
Colon Cancer TestsAverage Risk
Average Risk IndividualsNo SymptomsAge 50No risk factors
Current RecommendationsAverage Risk*Preferred strategy by ACG
TestInterval (years)FOBTYearlySigmoidoscopyEvery 5 FOBT + SigmoidoscopyYearly, every 5ColonoscopyEvery 10*Barium enemaEvery 5
Approach to Colon Cancer TestingAsymptomaticMen and WomenYES family Hx
The flat polyp
Techniques to improve detectionNarrow-band imagingChromoendoscopyEndocytoscopySoitenko et al. JAMA March 2008
Narrow Band Imaging
Left sided ulcerative colitis
Ulcerative colitis with extensive pseudopolyps
FAMILIAL POLIPOSIS COLIIt is a rare autosomal dominant disorderMultiple colorectal polypsRectal bleeding/ change in bowel habitThe treatment- colorectal removal with ileoanal anastomosis, or panproctocolectomy with definitive ileostomy
Peutz-Jeghers syndromeIt 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 comparedwith that of the general population. Such cancer locations includes gastrointestinal and extraintestinal sites.
******What are the risk factors for colon cancer?
While the exact cause of colon cancer is not known, research shows it occurs more often among men and women over age 50. Nearly 90 percent of colon cancer patients are over the age of 50. Therefore, age is the primary risk factor.
Other factors include:
Family or personal history of colon cancer or polypsChronic inflammatory bowel diseaseHereditary colorectal syndromesUse of cigarettes and other tobacco productsHigh-fat/low fiber dietPhysical inactivity *What are the symptoms of colon cancer?While colon cancer can be treated successfully if caught early, symptoms may not appear UNTIL the disease is advanced. Early colon cancer usually has no symptoms.
Symptoms associated with colon cancer may include:
A change in bowel habits lasting more than a few daysBleeding from the rectumBlood in the stoolCramping or gnawing stomach painsWeakness or fatigueJaundice (yellow-green color of the skin & white part of the eye)While these signs may not necessarily point to colon cancer, its always better to be safe and seek your doctors advice if you, a friend or family member experience symptoms like these. *Why is it so important to get tested for colon cancer?Testing offers a powerful opportunity for the prevention, early detection, and successful treatment of colon cancer. Yet the majority of Americans aged 50 and older do not follow the ACS recommended testing guidelines for colon cancer.
Following the testing guidelines for colon cancer can help detect pre-cancerous polyps. Removing the polyps can lower a persons risk by preventing some colon cancers before they are fully formed.
Since some colon cancers cannot be prevented, finding them early is the best way to improve the chance of a cure and reduce the number of deaths.
When colon cancers are detected at an early stage and have not spread beyond the colon or rectum, the five-year survival rate is 90 percent. ******