LB Disease, Colonic Polyps and CA

Question 1

What is the association btwn colon polyps and colon cancer?

Answer 1

Colon cancers are believed to arise from adenomatous polyps (and ultimately the colon epithelia)

Question 2

What are the types of colon polyps?

Answer 2

Hyperplastic (non-neoplastic)

Adenomatous (tubular, tubulovillous and villous)

Question 3

What should be known about adenomatous polyps?

Answer 3

Large, villous adenomas have highest malignant potential
Progression to cancer from early adenoma takes approximately 10 yrs
Almost all colon cancers arise from adenomas
Only 1% of adenomatous polyps ever become malignant

Question 4

What are the risk factors for colon cancer?

Answer 4

Age > 50
Personal hx of CRC or adenomatous polyps
Family hx of CRC
IBD
Ulcerative Colitis
Crohn's Dz
Familial colon cancer syndromes

Question 5

What is familial adenomatous polyposis (FAP)?

Answer 5

Autosomal dominant syndrome resulting from mutation in the APC gene
Hundreds of adenomas in the colon
Nearly 100% risk of cancer if not treated
Pts usually require a colectomy at young age
Annual flex sig beginning age 10-12

Question 6

What is Hereditary non-polyposis colorectal cancer (HNPCC or Lynch Syndrome)?

Answer 6

Occurrence of CRC in at least three 1st degree relatives over at least 2 generations with at least 1 person diagnosed < age 50
Screening colonoscopy at age 20-25 or 10 years earlier than youngest age of diagnosis in family