Colorectal CA

Question 1

2 Polyp types are RISK FACTORS Colorectal cancer

Answer 1

Adenomatous and serrated polyps,

Question 2

4 RISK FACTORS CRC

Answer 2

1. familial cancer syndromes,
2. IBD,
3. tobacco use,
4. diet of processed meat with low fiber.

Question 3

MC locations

Answer 3

Rectosigmoid > ascending > descending.

Question 4

Location for exophytic mass, iron deficiency

anemia, weight loss.

Answer 4

Ascending

Question 5

Location for infiltrating mass,

Answer 5

Descending

Question 6

Location for: iron deficiency

anemia, weight loss.

Answer 6

Ascending

“Right side bleeds”

Question 7

Location for: obstruction, colicky pain.

Answer 7

Descending

“left side obstructs”

Question 8

Bacteremia for CRC

Answer 8

Streptococcus bovis

Question 9

Raises suspicion in males v females?

Answer 9

Iron deficiency anemia in
males (especially > 50 years old)
and
postmenopausal females

Question 10

Screen patients 4 ways

Answer 10

Screen patients > 50 years old with

1. colonoscopy A ,
2. flexible sigmoidoscopy,
3. fecal occult blood test, or
4. fecal DNA test.

Question 11

lesion appearance seen on barium enema x-ray B .

Answer 11

“Apple core”

Question 12

tumor marker:

Answer 12

CEA

Question 13

CEA good for what?

Answer 13

Good for monitoring recurrence, should not be used for screening.

Question 14

3 Molecular pathogenesis of colorectal cancer

Answer 14

1. FAP
2. Lynch syndrome
3. serrated polyp pathway

Question 15

Chromosomal instability pathway: mutations in APC cause what kind of polyp dz.?

Answer 15

FAP

Question 16

Microsatellite instability pathway: mutations or methylation of mismatch repair genes (eg, MLH1) cause what polyp syndrome?

Answer 16

Lynch syndrome

Question 17

Chromosomal instability pathway 3 events to form carcinoma in CRC?

Answer 17

1. Loss of APC gene
2. KRAS mutation
3. Loss of tumor suppressor gene(s) (p53, DCC)

Question 18

Loss of APC gene causes

Answer 18

↓ intercellular adhesion ↑ proliferation

Question 19

KRAS mutation causes

Answer 19

Unregulated intracellular signaling

Question 20

Loss of tumor suppressor gene(s) (p53, DCC) causes

Answer 20

tumor formation