Colorectal Cancer Clinical Management Flashcards
What should you think of with a 57 yo male presenting with fatigue who has a hemoglobin of 10 an a microcytic anemia?
iron deficiency anemia secondary to GI blood loss = colorectal cancer until proven otherwise
What is the main diagnostic test for a patient like that?
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
What are some other options for imagine? And what are the main issues with them?
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)
What do you absolutely need in order to make a diagnosis?
tissue biopsy
Our patient has an adenocarcinoma in the cecum. what’s next?
CT scan to look for metastasis
CEA level (but will be possitive in all liklihood)
Surgery to remove that second of the colon
Who does the staging of colon cancer?
the pathologists
What is stage I CRC?
mass is only intraluminal and hasn’t invaded through the whole depth of the wall?
WHat makes a CRC stage II?
invasion through the whole depth of the wall
What makes a CRC stage II?
nearby lymph node involvement
What makes a CRC stage IV?
distant metastasis to retroperitoneal nodes or other organs
What organ will et mets first in colon cancer that does not affect the rectum?
the liver (portal hematogenous spread)
What organ will get metes first in rectal cancer?
lungs (caval hematogenous spread)
Why is prognosis for stage IIb worse than IIa?
In IIb it hs perforated the colon wall, which is a clinical marker of a tumor that will behave badly
Are all stage 4 CRC incurable?
no - a small subset can still be cured fi the metastasis only affects the liver
Pearl: what stage is a rectal cancer with an enlarged inguinal node?
stage 4 - its metastatic by definition
Most patients with CRC will present with what stage?
II (25%) or II (33%)
What is the typical chemotherapy cocktail for CRC?
5-fluorouracil
leukovorin
oxaliplatin (better for Stage III than II oddly enough)
What are the considerations that make a stage II CRC “high-risk”?
- T4 tumors
- obstruction/perforation fo the bowel
- lymphatic or vascular invasion
- undifferentiated histology
- less than 10 lymph nodes retrived (you want at least 12)
Why is the distinction of
“high risk” for the stage IIs important?
because regular stage II can just be treated with surgery, high risk should get chemo
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?
genetic testing - the readout will tell you the risk of recurrence in 3 years
What is the physical exam follow up recommendation after CRC?
every 3 months for 2 years, then every 6 months for 3 years
What are the CEA test recommendations for follow up?
every 3 months for 2 years, then every 6 months for 3 years for T2, T3 and T4 tumors
When should you get a follow-up colonoscopy?
1 year and repeate every 1 year if abnormal polyps are noted
then every 3-5 years if negative
What do you have to check for before you use EGFR antibodies like cetuximab or panitumubab?
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
