colorectal cancer

Question 1

strong RF for CRC (5)

Answer 1

• hereditary colon cancer syndrome
• personal hx of CRC, adenamtous polyps
• over 50+ older
• long standing UC or crohns)

Question 2

5 sx of CRC

Answer 2

Occult blood in stool or bright red blood per rectum
Iron deficiency anemia
Change in caliber of stools
Constipation or diarrhea
Unexplained weight loss

Question 3

what does CRC look like on plain film/barium enema

Answer 3

apple core lesions

Question 4

how is CRC diagnosed?

Answer 4

CAT scan then colonoscopy

Question 5

3 other imaging and testing you can do after diagnosing CRC

Answer 5

CT chest/abdomen/pelvis w/ IV contrast
Rectal US or pelvic MRI for rectal cancer staging
CEA level (serum tumor marker)

Question 6

CRC Surveillance after diagnosis (3)

Answer 6

• CEA levels q 3-6 months x 5 years
• CT yearly x 5 years
• colonoscopies before tx, 1 yr after tx. if normal then repeat in 3 yrs. if normal then q 5 yrs

Question 7

who in the normal risk pop. should be screened for CRC? how?

Answer 7

• all adults 45-75 should be screened, after that decide w/ provider
• annual guaiac-based FOBT or immunochemical FOBT (FIT) or colonscopy q 10 years

Question 8

1 FDR w/ cancer or advanced polyp under 60 yrs at time of diagnosis OR 2 FDR @ any age

Answer 8

colonoscopy Q 5 yrs at 40 or 10 yrs before youngest affected relative

Question 9

1 FDR over 60

Answer 9

colonoscopy Q 10 after 40, continue regular screening

Question 10

Autosomal dominant germline mutation in DNA mismatch repair genes
microsatellite instability (MSI) in their tumors

what is this condition? when do you do colonoscopies?

Answer 10

lynch syndrome at 25
colonoscopy Q 1-3 yrs; skin exam for cancer

Question 11

Autosomal dominant germline mutation in APC gene; Also at risk for duodenal and gastric polyps

what is this condition? when do you screen & how? treatment?

Answer 11

familial adenomatous polyposis
initial screen at age 10-12 w/ flexible sigmoidoscopy yearly
Prophylactic total colectomy often performed (will get CRC by age of 45 if they don’t) & refer to gastroent. for continued surveillance

Question 12

most common neoplastic polyp that should be resected completely

Answer 12

adenomatous

Question 13

most common non-neoplastic polyp; serrated and benign

Answer 13

hyperplastic

Question 14

non-neoplastic stromal & epithelial components as well as inflammatory cells

what is this

Answer 14

pseudopolyps– dont need to be excised

Question 15

surgery for colon vs rectal cancer

Answer 15

• colon: hemicolectomy
• rectal: low anterior resection or abdominoperineal resection

Question 16

what stage is chemo typically added

Answer 16

stage 3

Question 17

what can be done before surgery for rectal cancer? when do you do this?

Answer 17

neoadjuvant 5-fu/leucovorin chemo, radiation if metastasized to nodes

Question 18

tx of node metastasis (colon vs rectal)

Answer 18

Colon CA: Surgery + chemotherapy
Rectal CA: neoadjuvant chemo/radiation

Question 19

which has better survival– colon or rectal

Answer 19

colon cancer

Question 20

test that looks for blood in stool, done yearly but not great for precancers since those dont bleed

pros of this test?

Answer 20

FOBT
pros: no risk to colon and no prep or sedation

Question 21

test that requires diet change to avoid things like beef blood from being picked up

Answer 21

guaiac FOBT

Question 22

reacts to globin (not heme); more specific than gFOBT and needs no dietary restrictions; done yearly

Answer 22

fecal Immunochemical Testing (FIT)

Question 23

looks for blood and DNA shed from colon polyps and cancers in stool; done every 3 yrs; very sensitiv for cancer

Answer 23

stool DNA (cologuard); same pros/cons as FOBT

Question 24

done in clinic to look for polyps and cancers; does NOT need full bowel prep or sedation; views left 1/3 of colon

Answer 24

flexible sigmoidoscopy– v small risk of bleeding & perforation

Question 25

Does not report polyps under 5 mm so return after 5 yrs if negative; takes 10 mins and does not need sedation; sees ENTIRE colon; no need to stop anticoags

Answer 25

CT colonoscopy; needs bowel prep