Colorectal Cancer Clinical Management

Question 1

What should you think of with a 57 yo male presenting with fatigue who has a hemoglobin of 10 an a microcytic anemia?

Answer 1

iron deficiency anemia secondary to GI blood loss = colorectal cancer until proven otherwise

Question 2

What is the main diagnostic test for a patient like that?

Answer 2

colonoscopy!

other options for detection of colon cancer are useless when the index of suspicion is so high because they’ll likely be positive and you’ll end up doing the colonoscopy anyways

Question 3

What are some other options for imagine? And what are the main issues with them?

Answer 3

flexible sigmoidoscopy (only see sigmoid)
virtual colonoscopy (can miss things and can't biopsy)
barium enema (can miss things and cn't biopsy)
FIT - fecal immunological test (only a screening test and can't biopsy)

Question 4

What do you absolutely need in order to make a diagnosis?

Answer 4

tissue biopsy

Question 5

Our patient has an adenocarcinoma in the cecum. what’s next?

Answer 5

CT scan to look for metastasis

CEA level (but will be possitive in all liklihood)

Surgery to remove that second of the colon

Question 6

Who does the staging of colon cancer?

Answer 6

the pathologists

Question 7

What is stage I CRC?

Answer 7

mass is only intraluminal and hasn’t invaded through the whole depth of the wall?

Question 8

WHat makes a CRC stage II?

Answer 8

invasion through the whole depth of the wall

Question 9

What makes a CRC stage II?

Answer 9

nearby lymph node involvement

Question 10

What makes a CRC stage IV?

Answer 10

distant metastasis to retroperitoneal nodes or other organs

Question 11

What organ will et mets first in colon cancer that does not affect the rectum?

Answer 11

the liver (portal hematogenous spread)

Question 12

What organ will get metes first in rectal cancer?

Answer 12

lungs (caval hematogenous spread)

Question 13

Why is prognosis for stage IIb worse than IIa?

Answer 13

In IIb it hs perforated the colon wall, which is a clinical marker of a tumor that will behave badly

Question 14

Are all stage 4 CRC incurable?

Answer 14

no - a small subset can still be cured fi the metastasis only affects the liver

Question 15

Pearl: what stage is a rectal cancer with an enlarged inguinal node?

Answer 15

stage 4 - its metastatic by definition

Question 16

Most patients with CRC will present with what stage?

Answer 16

II (25%) or II (33%)

Question 17

What is the typical chemotherapy cocktail for CRC?

Answer 17

5-fluorouracil
leukovorin
oxaliplatin (better for Stage III than II oddly enough)

Question 18

What are the considerations that make a stage II CRC “high-risk”?

Answer 18

1. T4 tumors
2. obstruction/perforation fo the bowel
3. lymphatic or vascular invasion
4. undifferentiated histology
5. less than 10 lymph nodes retrived (you want at least 12)

Question 19

Why is the distinction of

“high risk” for the stage IIs important?

Answer 19

because regular stage II can just be treated with surgery, high risk should get chemo

Question 20

What tool do you have to determine if a stage II tumor should get adjuvant chemo? Especailly is the lymph nodes didn’t pan out?

Answer 20

genetic testing - the readout will tell you the risk of recurrence in 3 years

Question 21

What is the physical exam follow up recommendation after CRC?

Answer 21

every 3 months for 2 years, then every 6 months for 3 years

Question 22

What are the CEA test recommendations for follow up?

Answer 22

every 3 months for 2 years, then every 6 months for 3 years for T2, T3 and T4 tumors

Question 23

When should you get a follow-up colonoscopy?

Answer 23

1 year and repeate every 1 year if abnormal polyps are noted

then every 3-5 years if negative

Question 24

What do you have to check for before you use EGFR antibodies like cetuximab or panitumubab?

Answer 24

the cancer MUST be k-ras wild-type in order or them to work (but that doesn’t mean they will work)

k-ras mutations mean the cells have already learned how to skip the EGFR signalling and they’re proliferating without it

Question 25

What commonly use OTC med can be used to prevent adenomas in FAP and families with prior colon cancer?

Answer 25

aspirin! or the other COX inhibitors

Question 26

What stages should always reeive chemo?

Answer 26

stage III and IV