Cancer: Colorectal Flashcards Preview

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Flashcards in Cancer: Colorectal Deck (18):
0

What are the types of stem cells in the small bowel and colon?

(1) position +4 cells (quiescent)
(2) columnar basal cells (active)

1

What notable cell type is present in the small bowel epithelium but not in the colon?

Paneth cell.

2

J: This refers to an area of self-limited hyper proliferation in the small bowel or colonic epithelium.

What is an aberrant crypt focus?

3

What oncogenes are associated with colorectal cancer?

(1) K-ras
(2) myc
(3) src

4

What tumor suppressors are associated with colorectal cancer?

(1) APC
(2) p53
(3) DPC4
(4) DCC
(5) MCC
(6) beta-catenin

5

What genetic lesion is the initial insult in most sporadic colon adenomas and carcinomas?

Inactivation of APC.

6

Which gene is mutated in familial adenomatous polyposis?

APC.

7

What ultimately results from normal Wnt signaling?

(1) increased, controlled proliferation
(2) decreased apoptosis

8

What are some genes that are particularly susceptible to mutation when there is a mismatch repair deficiency?

Genes having a polyA tail: TGFBRII, Bax, MSH6.

9

Does a mismatch repair deficiency cause cancer?

Not really, it allows mutations to regulatory genes to persist which can lead to cancer.

10

How does the expression of COX-2 change in colorectal cancer?

It increases, promoting tumor growth and survival.

11

What profile is at increased risk of colorectal cancer?

An aging individual with a high-fat, low-fiber diet, IBD, and a personal or familial history of CRC or adenomas.

12

What is the average age of onset of polyps in FAP?

16.

13

Where are extra colonic tumors likely to develop in FAP?

(1) upper GI
(2) connective tissue (desmoid)
(3) bone (osteoma)
(4) thyroid
(5) brain
(6) skin

14

What is Gardner's syndrome?

A variant of FAP that includes extraintestinal lesions:
(1) desmoid tumors
(2) osteomas
(3) supernumerary teeth
(4) sift tissue skin tumors
(5) CHRPE

15

Where tumor most commonly found in Lynch syndrome?

The proximal colon.

16

What extra colonic cancers are seen in individuals with Lynch syndrome?

(1) endometrium
(2) ovary
(3) stomach
(4) urinary tract
(5) small bowel
(6) pancreas
(7) bile ducts
(8) CNS
(9) sebaceous skin tumors

17

What are accepted methods for screening for colorectal cancer?

(1) fecal occult blood testing
(2) fecal immunochemical testing
(3) flexible sigmoidoscopy
(4) colonoscopy
(5) barium enema