Exam 2 - Colon Cancer Flashcards
Compare a pedunculated and a sessile colon polyp.
Pedunculated - attached by stem/stalk
Sessile - Flat
What is the most common adenoma classification of colon polyps?
Tubular adenoma
What is an emerging type of pre-cancerous polyp?
Sessile serrated polyp
What is the most common origin site of CRC?
Left-sided colon
What is the most common clinical presentation associated with CRC?
Asymptomatic
What are some red flag symptoms associated with the clinical presentation of CRC?
- Change in bowel habits
- Hematochezia or occult blood in stool
- Iron Deficiency Anemia
- Anorexia/Weight loss
- Abdominal pain
What is a classic finding on imaging to support colon cancer?
“Apple core” lesion
What does the TNM system stand for?
Tumor
Node
Metastasis
What are some hereditary risk factors associated with CRC?
- Adenomas or colon cancer
- FAP (Familial adenomatous polyposis)
- HNPCC (Hereditary nonpolyposis colon cancer)
What is the management of CRC?
- Partial colectomy
- Chemotherapy (if metastasis present)
- Radiation (commonly used for rectal adenocarcinoma)
What is included in surveillance of CRC?
- Serial CEA levels
- Annual CT chest/abd/pelvis
- Periodic colonoscopy
What types of visualization tests are recommended for the screening of CRC?
- Colonoscopy
- Flex Sigmoidoscopy
- CT Colonography
What types of stool-based tests are recommended for the screening of CRC?
- gFOBT
- FIT
- FIT-DNA
What is the gold standard diagnostic screening test for CRC?
Colonoscopy
What is a major advantage of a colonoscopy in regards to CRC screening?
- Able to both detect and remove polyps to prevent them from turning into cancer
- Only screening test that is preventative
What is a major disadvantage of a Flex Sigmoidoscopy in regards to CRC screening?
Deficiency in protection against proximal lesions (only goes through distal 1/3 of colon)
What is a major disadvantage of a CT Colonoscopy in regards to CRC screening?
Can miss flat or small polyps (<10 mm - 1 cm)
What is a major disadvantage of using both the gFOBT and FIT stool tests in regards to CRC screening?
Sensitivity for one-time screening is not ideal, annual use recommended
What is the preferred CRC detection test if patient refuses a scope?
FIT (stool-based)
What is a disadvantage of all stool-based CRC screening tests?
- Positive results require follow-up colonoscopy
- Adenomatous polyps usually do not bleed, thus can be missed by tests that assess for hemoglobin in stool
At what age should screening for CRC generally begin in a patient with no risk factors?
Age 50
When should you start CRC screening for those with increased risk related to family history or IBD?
Colonoscopy every 5 years beginning at age 40 or 10 years younger than the age at which the youngest 1st degree relative was diagnosed (whichever comes first)
Single 1st degree relative w/ CRC or advanced adenoma dx > 60 y/o
- Being screening at age 40 and if normal, screen as a average risk individual
IBD:
- Screening begins 8-10 years after onset of symptoms
Discuss some etiology behind FAP?
- > 100 adenomatous polyps
- Polyp emergence begins at around 16 years of age
- Nearly 100% will develop CRC by around 39 years of age if left untreated
- Increased risk of extracolonic malignancies
What is typically recommended with FAP?
Prophylactic colectomy
What is the screening protocol for FAP?
- Sigmoidoscopy/Colonoscopy starting at age 10-12 and repeating every 1-2 years
- Routine EGD
- Screen for extracolonic malignancies (thyroid ultrasound, etc.)
Discuss some etiology behind HNPCC?
- Usually right-sided CRC; aged 45-60 years of age
- Multiple family members affected
- Increased risk of multiple cancers (endometrial most common)
What is the Amsterdam Criteria associated with the diagnosis of HNPCC?
“3-2-1 rule” (3 affected family members, 2 generations, 1 under age 50)
What screening is recommended with HNPCC?
- Annual colonoscopy beginning between the ages of 20-25 or 2-5 years prior to th earliest age of CRC diagnosis in the family (whichever comes first)
- Screen for other extracolonic malignancies (pelvic exam with endometrial biopsy and transvaginal US, EGD)
When should you consider Hereditary Colon Cancer Syndromes?
- Family hx of CRC in > 1 family member
- Personal or FH of CRC at early age (< 50 years)
- Personal or FH of multiple adenomas (> 10-20)
- Personal or FH of multiple extracolonic malignancies