Colon CA

Question 1

How do you classify colon polyps histologically? Which 2 kinds are pre-cancerous?

Answer 1

1. Hyperplastic
2. Pseudopolyps
3. Adenomas (pre-CA!)
4. Sessile serrated (pre-CA!)

Question 2

What are characteristics of adenomas?

Answer 2

2/3 of all polyps
Asx
> 50 yo
Early detection is key

Question 3

70% of CRCs arise from….

Answer 3

adenomas!

Question 4

What are characteristics of “high risk” adenomas?

Answer 4

≥ 10mm
Villous
High grade dysplasia

Question 5

Risk of CRC increases by _______, _______, & ______

Answer 5

of adenomas, size, & histology

Question 6

What is the MC presentation of CRC?

Answer 6

Often asx or left sided!

however, right sided colon CA is rising!

Question 7

What are major RFs for CRC?

Answer 7

Personal or fam hx
Age > 50
IBD > 8-10 yrs
African American

Question 8

What are red flags?

Answer 8

Change in bowel habits 
Hematochezia or occult blood 
Iron deficiency anemia 
Anorexia/wt loss 
Abd pain

Question 9

What does CRC look like on PE?

Answer 9

Cachetic

Pallor skin

Lymphadenopathy

Distended abd, ascites, abd mass, organomegaly

Hemoccult +, rectal mass

Question 10

What labs are used to assist w/ the dx of CRC?

Answer 10

CBC: Look for IDA

LFTs: Elevated alk phos can indicate liver mets

CEA: prognostic indicator & monitors for recurrence

Question 11

What procedure/imaging should be performed for CRC?

Answer 11

Gold = Colonoscopy (diagnostic & therapeutic!)

Chest/abd/pelvic CT

Question 12

What is seen on radiologic imaging in CRC?

Answer 12

Apple core lesion

Question 13

What system is used for staging in CRC?

Answer 13

TNM system (0-4 stages)

Question 14

How do you manage CRC?

Answer 14

Partial colectomy w/ wide margins & adjacent LN removal

Chemo (if mets present)

Radiation

Question 15

What should you continue to monitor after CRC therapy?

Answer 15

Serial CEA levels every 3-6 months for 3-5 yrs

CT chest/abd/pelvis annually

Colonoscopy within 1 year of resection

Question 16

What are 3 preventative tests for CRC?

Answer 16

Colonoscopy
Flex Sig
CT colonography

Question 17

What are 3 stool tests for CRC? Which is preferred?

Answer 17

gFOBT
FIT (preferred!)
FIT-DNA

Question 18

What are the cons of CT colonography?

Answer 18

Can miss flat or smaller polyps

If +, requires colonoscopy

Bowel prep

Radiation

Question 19

What is the con of stool tests?

Answer 19

Most polyps don’t bleed!

Question 20

When should you start screening for CRC in “average risk, asx” patients?

Answer 20

At age 50

Age 45 for African Americans

Question 21

Which CRC tests should be performed first, according to MSTF?

Answer 21

Colonoscopy & FIT

Question 22

When should you start screening for CRC in “increased risk” patients?

Answer 22

See slide 50

Basically begin screening at age 40. If pt has a relative who was diagnosed before age 60, you have another option - start screening pt 10 years prior to his/her relative’s age of dx
(choose whichever comes 1st).

Question 23

When should you discontinue CRC screening?

Answer 23

Considered when: 
Up to date w/ screening
Negative prior screening 
Age 75
Life expectancy < 10 yrs

Question 24

In general, how often should CRC screening tests be performed?

Answer 24

Colonoscopy every 10 yrs
CT colonography every 5 yrs
Flex Sig every 5-10 yrs

gFOBT annually
FIT annually
FIT-Fecal DNA every 1-3 yrs

Question 25

What are characteristics of familial adenomatous polyposis (FAP)

Answer 25

autosomal dominant APC gene mutation > 100 adenomatous polyps Begins at 16 yo Increased risk of extracolonic malignancies

Question 26

Why is a prophylactic colectomy recommended for FAP?

Answer 26

Will develop CRC by age 39 if untreated

Question 27

What are examples of extracolonic malignancy in FAP?

Answer 27

Gastric/duodenal/ampullary carcinoma Follicular/papillary thyroid CA Hepatoblastoma CNS tumors

Question 28

Who should you screen for FAP? What does screening consist of?

Answer 28

Gene carriers or those w/ fam hx w/out genetic confirmation Sigmoidoscopy/colonoscopy annually starting 10-12 yo until 40 Routine EGD recommended

Question 29

What are characteristics of HNPCC (Lynch Syndrome)?

Answer 29

Autosomal dominant Increased risk for CRC, aged 45-60 Increased risk of multiple cancers (endometrial MC)

Question 30

What criteria is used for dx of HNPCC?

Answer 30

``` Amsterdam criteria "3-2-1 rule" - At least 3 relatives - At least 2 generations - 1 dx before age 50 ```

Question 31

How do you screen for HNPCC?

Answer 31

Colonoscopy every 1-2 yrs beginning 20-25 yo or 2-5 yrs prior to earliest age of onset of affected relative (whichever comes 1st)