Colon Cancer screening

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Colon Cancer screening

• Susan M. Lepinski, M.D.

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Screening Goals

• Decrease colon cancer risk
• Find earlier and more favorable prognosis

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Colorectal Cancer

• 4th most common CA
• 2nd leading cause CA death
• 140-160,000/yr
• 50-60,000 deaths/yr

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Screen asymptomatic

• Adenoma-------------Cancer
• Adenoma is asymptomatic
• Screen asymptomatics

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DOING SOMETHING IS ALWAYS BETTER THAN DOING
NOTHING

• Provide screening

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Patient acceptance

• Cost
• Risk
• Availability

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Definition of Screening

• Asymptomatic
• Average risk 70
• Increased risk 30
• 95 of all colon cancer in average risk

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Average risk screening

• Age 50
• FOBT
• Flex sig
• FOBT and Flex sig
• BE----no
• CT Colonography??
• Colonoscopy preferred

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FOBT

• If positive, colonoscopy
• Guiac based
• 2 samples/3 consecutive stools
• Dietary restriction
• No rehydration

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Single digital rectal hemoccult

• NOT recommended
• Sensitivity 4.9 vs. home test 23.9

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NO FOBT if patient in colonoscopy screening
program
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Flex Sig

• Every 5 years
• If adenoma, colonoscopy
• Detection rate advanced neoplasia 3 times greater
  that FOBT
• Does not find right sided lesions

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1463 asymptomatic females

• 34.7 with advanced neoplasia had distal adenomas

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VA Study, males

• 70.3 advanced neoplasia FS
• 75.8 FOBT and FS

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Colonoscopy

• Every 10 years
• Preferred method
• Decrese risk CRC 76-90

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Norway Study

• 399no screen
• 400-FS-polyp-colonoscopy
• 13years---both groups---colonoscopy
• RR 0.2 prior colon

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Direct evidence

• NO study available to show DIRECT evidence any
  form of screening decreases mortality from CRC

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Accuracy of Colonoscopy

• Rex n200
• 6 miss rate 1 cm or greater lesion
• 1 rectal cancer missed

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CT Colonography
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CT

• Prep
• Discomfort
• Cost
• Radiation Exposure
• Sensitivity/specificity

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Meta-analysis CT

• 33 studies
• Sensitivity and specificity varied by polyp size

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Extraluminal lesions

• Incidental findings
• Further studies

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DCBE

• NOT recommended
• Inferior sensitivity
• Compared to colonoscopy sensitivity for 1 cm
  lesion 48

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Summary average risk

• DO SOMETHING
• Preferred is colonscopy age 50 and every 10 years

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Personal history

• Crohns
• CUC

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FAP

• Genetic Testing
• If positive, annual Flex Sig age 10

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HNPCC

• Early CRC
• Lynch
• Genetic testing
• Colon every 1 to 2 years age 20-25

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FMH CRC or adenomatous polyps

• First degree relative regardless of age
• Colon age 40 or 10 years less than youngest
• Follow up
• Less than 60 every 5 years
• Over 60 every 10 years

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Adenomas

• Same as for CRC
• Exception is first degree relative over 60

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Personal history CRC

• 6 months postop if cecum not reached
• Otherwise 1 year, 3 years, than every 5 years

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Personal history of adenomatous polyps

• Every 5 years
• Poor prep
• More than 3 polyps
• Large or flat polyps

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Meta-analysis

• 33 studies with CT
• polyp 6 mm polyp 6-9 mm
• Sensitivity
• specificity