shaimaa m.nagy faculty of medicine, benha university
TRANSCRIPT
Screening and Early Diagnosis of
Colorectal Cancer
Shaimaa M.NagyFaculty of Medicine, Benha University
Incidence of CRCCRC is the 3rd most common form of cancer diagnosed
in men and women in the USCRC is the 2nd leading cause of cancer deaths in the USThe number of people dying from CRC has declined
over the past 20 years with better screening, diagnosis and treatments
ch.ch. of CRC in Egypt:
• Relative frequency 10-12%• High male predominance 3:1• More than 1/3 under age 45 (early onset)• Large tumor size 4.5 cm• rectal 51%, poor histology 58%• Associated bilharzial colitis 12%• Associated polyps 5%• Sporadic , HNPCC
Symptoms and signs A change in bowel habits: diarrhea, constipation, or a feeling that
the bowel does not empty completely
Bright red or dark blood in the stool
Stools that appear narrower or thinner than usual
Discomfort in the abdomen, including frequent gas pains, bloating, fullness, and cramps
Unexplained weight loss, constant tiredness, or unexplained anemia (iron deficiency)
Colorectal Cancer
80% present with early disease
20% present with metastatic disease.
Among patients diagnosed with early-stage disease, 40% will suffer recurrence.
Stage at Diagnosis
Localized(Stage I/II)
50%
Distant(Stage IV)
20%
Regional(Stage III)
30%
Risk Factors for CRC
• Age >50 (average risk)• Racial, ethnic factors
– African-Americans have increased risk• Dietary factors
– high animal fat, low fiber diet• Lifestyle
– Sedentary– Obesity– Smoking– Alcohol
-genetic factors-sporadic
Lifestyle Risk Factors for Colorectal Cancer
· Decrease Risk- Exercise- Folic acid- Aspirin- Calcium, vitamin D- Screening
· Increase Risk- Obesity- Red meat- Alcohol- Smoking
Colorectal Cancer (CRC)
Sporadic (average risk) (75-80%)
Familyhistory(10-15%)
Hereditary non-polyposis colorectal cancer (HNPCC)
(3-5%)Familial adenomatous polyposis (FAP) (1-2%)
Rare syndromes
(<0.1%)
Precancerous lesions:
PolypsIBD
Histological classification of polypstype single multiple
neoplastic Adnoma ( T,V,TV)adenocarcinoma
adenomatosis
hyperplastic hyperplastic Hyperplastic polyposis
hamartomatous Juvenile polypPeutz-jegher syndrom
Peutz jegher cowden
inflammatory Parasiticpsuedolymphoid
Parastic, inflammatory
Natural History
Polyp Advanced cancer
• Age 50, 25% risk of developing polyps• Age 75, 50-75% risk of developing polyps
IBD: Classification of Dysplasia
• Negative for dysplasiaNormalInactive colitisActive colitis• Indefinite for dysplasia• Positive for dysplasiaLow-grade dysplasiaHigh-grade dysplasia
Carcinoma in InflammatoryBowel Disease
• Extensive colitis 13%• < 10 years < 1%• 15 years 4.5%• 20 years 13%• 30 years 34%• Crohn’s disease 3%
Colorectal Cancer and Early DetectionColorectal cancer can be prevented through regular
screening and the removal of polyps
Early diagnosis means a better chance of successful treatment
Screening should begin at age 50 for all “average risk” individuals or sooner if you have a family history of colorectal cancer, symptoms, or a personal history of inflammatory bowel disease
Screening Methods for Colorectal Cancer History and general examination • Rectal examination
Colonoscopy (currently the best way to prevent and detect colorectal cancer)
Virtual colonography
Sigmoidoscopy
Fecal occult blood test
Double contrast barium enema
Digital rectal examination • Serum CEA, CA 19-9, CA 72.4 CBC, ESR, Ca and folic acid detection
Fecal Occult Blood Test (FOBT)Recommended to be done yearlyChecks for hidden blood in the stoolYour doctor gives you a test kit
At home, you place a small amount of your stool from 3 bowel movements on test cards.
You then return the cards to your doctor’s office or a lab where the stool samples are tested for hidden blood.
If blood is found, a colonoscopy will be needed.A disadvantage of this test
The test is often negative in people who have adenomatous polyps and colorectal cancer
Flexible Sigmoidoscopy (Flex Sig)Recommended every 5 yearsExamines the lining of rectum and lower part of colonUses a thin, flexible, lighted tube called a sigmoidoscope
It is inserted into your rectum and lower part of your colon.If polyps or lesions are found, a follow-up test is needed.
Disadvantages:Patient discomfort – but not painfulOnly looks at lower part of colon, therefore polyps in the
upper colon can go undetected.If a polyp is found, it needs to be followed by a colonoscopy to
remove the polyp
Combination FOBT and Flex SigSome experts recommend using both of these tests to
increase the chance of finding polyps and cancers. It is recommended every 5 years
ColonoscopySimilar to the Flexible Sigmoidoscopy except:
It allows the doctor to look at the lining of your rectum and entire colon.
Done as an outpatient procedureDone with “conscious sedation”
An IV line is inserted to help you remain calm and comfortable. Some patients sleep though the procedure.
Not everyone needs sedation. Uses a thin, flexible, lighted tube called a colonoscopeIt is inserted into your rectum and colon. The doctor can also find and remove polyps and some cancers
using the colonoscope. It is recommended every 10 years for:
Individuals with no family or personal history of colon cancer and no symptoms.
Colonoscopy (continued) …Procedure takes 15–30 minutes.May take longer if polyps are removed.
Called a polypectomy A wire loop is passed through the scope to cut the polyp
from the lining of the colon using an electrical current. Polyps are collected and sent to the
lab for evaluation.
Double Contrast Barium Enema (DCBE)This test allows the doctor to see an x-ray image of
the rectum and entire colon.First you are given an enema with a liquid called
barium that flows from a tube into your colon, followed by an air enema.
The barium and air create an outline around your colon, allowing the doctor to see if anything is wrong.
Recommended every 10 years. Many disadvantages:
Detects only 50 percent of adenomatous polyps greater than 1 cm in size and only 33 percent of polyps .5 cm in size
May miss up to 15 percent of colorectal cancers
Does not allow removal of polyps
Take Home Message
Screening = Prevention & Early Detection
Prevention = polyp removalDecreased Incidence
Early Detection Decreased Mortality
THANK YOU