Colon cancer

  • Risk factors: family hx (Lynch, FAP), age, race (black > white), gender (M > F), IBD, prior CRC or polyps, abdominal radiation for childhood cancer

Screening

Risk Screening

Average risk - none of the below; start asking ~ age 20

  • Personal hx of CRC or adenomatous polyp
  • First-degree relative with CRC or advanced adenoma (≥ 1 cm or high grade/villous elements)
  • Genetic predisposition -  hereditary nonpolyposis colorectal cancer (HNPCC/Lynch syndrome), familial adenomatous polyposis (FAP)
  • IBD (UC, Crohn's) causing pancolitis or active disease > 8-10 years
  • Other personal hx like childhood cancer w/ abdominal radiation
 Begin at age 50, stop ~ age 75-85 or if life expectancy < 10 yr
  • Colonoscopy q10 years if initial colonoscopy negative
  • CT colonography q5 years
  • FIT q1 year
  • Fecal DNA testing q3 years
  • gFOBT q1 year on 3 samples
  • Flex sig q10 years + FIT q1 year
  • Flex sig q5 years

Increased risk - 'yes' to any of the above conditions

Substantially increased risk

  • 1 first-degree relative with CRC, or advanced adenoma < 60 years old
  • 2 first-degree relatives diagnosed at any age

Colonoscopy q10 years starting at age 40, or 10 years younger than earliest diagnosed family member

Recommended to use colonoscopy instead of other screening methods
Lynch syndrome Colonoscopy q1-2 years starting at age 20-25, or 2-5 years younger than earliest CRC-diagnosed family member
FAP

Colonoscopy or flex-sig q1 years starting at age 10-12. Full colonoscopy should be done if adenomas are found.

Attenuated FAP: colonoscopy q1-2 years starting at age 25

Tests

Colonoscopy High sens/spec, able biopsy/remove polyps at the same time. Requiring aggressive bowel prep and conscious sedation.
CT colonography Nearly as sensitive as colonoscopy, but requires aggressive prep, and unable to biopsy/remove polyps
Flex sig Can only see distal 60 cm of bowel, but requires minimal prep/sedation
FIT More $ than guiaic, but better sens/spec. Mail in stool sample. No diet restrictions.
guaiac FOBT Low sens/spec, but cheap. Must be done w mail-in stool sample, not office rectal exam. Positive gFOBT x 1 is indication for timely colonoscopy. Should avoid NSAIDs and red meat for 7d prior.
Fecal DNA More $ than FIT but higher sensitivity. Lower specificity than FIT.

Capsule colonography?

 

Surveillance

Stage II/III
Clinic visits q3-6 mo for first 3 years; q6 mo for years 4-5. With rectal exam if LAR or trans-anal excision of rectal cancer
CEA q year for first 2-3 years
Colonoscopy 1 year after primary resection, then q3-5 years if normal
Stage I
Colonoscopy Interval
author: last edited: Aug. 1, 2018, 1:35 p.m. | pk: 128 | unpublished