2- Colon CA Flashcards
What is a growth on the inner surface of the colon?
Polyp
What type of polyp is attached by a stem/stalk?
Pendunculated
What type of polyp is flat?
Sessile
What types of polyps are benign?
Hyperplastic Pseudopolyps (inflammatory)
What types of polyps are malignant?
Adenomas
Sessile serrated polyps (pre-cancerous)
70% of all CRC arise from what type of polyp?
Adenomas
An adenoma will slowly transition to a carcinoma over 10 years. What is the best early treatment?
Early detection and removal
How is an “advanced” carcinoma defined?
≥ 1 cm
Villous component
High grade dysplasia
What are the 3 types of adenoma polyps? What is the most common?
Tubular adenoma = most common
Tubulovillous adenoma
Villous adenoma
Risk of CRC increases by what (3)?
of adenomas, size and histology
What is defined as a malignant growth on the inner wall of the colon or rectum?
Colorectal CA
What is the most common presentation of CRC?
Left sided colon cancer
Are rates of right sided colon CA rising or falling?
Rising
Early screening for CRC is recommended in what population?
African American
Clinically how will a pt w/ CRC present?
Often ASX
Change in bowel habits, blood in stool, IDA, weight loss, and abd pain are all what related to CRC?
Red flags
On exam of pt that presents w/ abd pain, you find the pt is cachectic, pale, + lymphdenopathy, abd distention & mass, and + hemoccult on DRE. What is the suspected dx and what is your next step?
CRC
Refer to GI for colonoscopy
Carcinoembryonic antigen (CEA) is a marker for what?
Tumor marker
Not used for screening, helpful as prognostic indicator and to monitor for recurrence
What study will permit biopsy for pathologic confirmation of CRC (dx and therapeutic)?
Colonoscopy
An apple core lesion on barium enema is concerning for what?
CRC
What staging sx is used for CRC?
Tumor: depth of tumor
Node: regional lymph node involvement
M: +/- mets
Staging 0-4
When is chemotherapy used in the TX of CRC?
Usually if mets are presents
When is radiation therapy used in the TX of CRC?
For rectal adenocarcinoma
What surveillance studies are used to tack CRC?
Serial CEA level, annual CT chest/adb/pelvis, periodic colonoscopy
The following are RF for what? Hereditary syndromes (FAP, HNPCC), PMHx or FHx of adenomas or CRC, PMHx IBD, and age > 50
CRC
FAP = Familial adenomatous polyposis HNPCC = Hereditary nonpolyposis colorectal cancer
What is the difference b/w screening vs surveillance?
Screening: process of detecting early stage CRC/preCA lesion in asx pts w/ no prior hx
Surveillance: follow up testing in pts w/ hx of polyps, CA, IBD
What screening tests will visualize the colon? (3)
Colonoscopy
Flex sigmoidoscopy
CT colonography
What screening tests are stool based?
gFOBT (hemocucult SENSA)
FIT
FIT-DNA
T or F: Barium enema, office-based stool guaiac, serology- Septin 9, and colon capsule endoscopy are recommended screenings tests for CRC?
FALSE
They are NOT recommended for screening
What screening test is gold standard (both diagnostic and therapeutic)?
Colonoscopy
What are the advantages of a colonoscopy? (5)
- Visualize entire colon
- Detect and remove polyps to PREVENT turning into CA
- High CRC sensitivity
- Single session
- Long screening intervals
What are the disadvantages of a colonoscopy? (6)
- Cost/time
- Bowel prep
- Invasive/complications
- Sedation
- Bowel prep influences adenoma detection ability
- Operator dependent
What will influence postpolypectomy surveillance?
of polyps, size, histologic features
*endoscopist provides recommendations for repeat scope
What CRC screening test only reaching the distal 1/3 of colon?
Flex sigmoidoscopy
Why has flex sigmoidoscopy fallen out of favor for CRC screening?
Does not offer protection against proximal lesions (right/proximal CRC increasing)
If polyps found, will need colonoscopy to r/o proximal lesions
What is the disadvantage of CT colonography?
Can miss flat or small polyps (<10 mm-1 cm)
Unable to remove polyps (will need colonoscopy if +)
Bowel prep
What are the advantages of CT colonography?
Lower risk of perf vs scope
No sedation
Able to use in pts w/ comorbidities or physiological abnormality
Do most polyps bleed?
NO!
Can be missed on tests that assess for hemoglobin in stool
What stool based screening tool requires 3 consecutive stool samples, dietary modifications, and has low sensitivity for one-time screening (annual recommended)?
gFOBT (highly sensitivity hemoccult SENSA)
What stool based screening tool tests for the presence of human hemoglobin, does NOT require dietary restrictions, and only requires single stool sample?
FIT
What stool based screening test is preferred for initial CRC detection test?
FIT
What stool based screening tool combines FIT w/ DNA testing (biomarkers for CRC), has higher false positives vs FIT and requires entire bowel movement/ is $$$$?
FIT-DNA
If pt w/ positive stool sample what is the next step?
Timely dx colonoscopy
What should you be mindful of with regard to stool based tests?
Lower sensitivity vs visualization tests, limit preventative role of screen, need multiple screens to be effective
At what age does screening for CRC begin?
45-50 based on various guidelines (45 y/o for AA)
At what ages does screening for CRC stop?
75 yrs or less than 10 yr life expectancy
When do you start screening Pt for CRC if +FHx (dx < 60)?
Colonoscopy every 5 yrs beginning at age 40 or 10 years younger than age at which youngest 1st degree relative was DX (whichever comes first)
When do you start screening Pt for CRC if +FHx (dx > 60)?
Begin screening at age 40. If normal then screen pt as avg. risk individual
When do you start screening Pt for CRC w/ IBD?
8-10 yrs after onset of sx
What hereditary disease is characterized by > 100 adenomatous polyps?
Familial adenomatous polyposis
Pts w/ Familial adenomatous polyposis will develops sx at ~ 16 yo, if left untx pts will develop what by age ~39?
CRC
What is the recommended tx for Familial adenomatous polyposis?
Prophylactic colectomy
Pts w/ Familial adenomatous polyposis are at an increased risk for what?
Extracolonic malignancies
- Gastric/duodenal/ampullary CA
- Follicular/papillary thyroid CA
- Hepatoblastoma (children)
- CNS tumors
When do you start screening for pt who are gene carriers of Familial adenomatous polyposis?
Sigmoidoscopy/colonoscopy starting at age 10-12 and repeating every 1-2 yrs
Routine EGD also recommended
Hereditary Nonpolyposis colon CA (HNPCC) is aka what?
Lynch syndrome
Pts w/ Hereditary Nonpolyposis colon CA (HNPCC) are at an increased risk for what?
- CRC (usually right sided) by age 45-60
- Multiple CA (endometrial = most common)
*Be sure to collect thorough FHx
What is the Amsterdam criteria for Hereditary Nonpolyposis colon CA (HNPCC)?
3-2-1 rule
3 affected family members
2 generations
1 under age 50
When should CRC screening start for pt that meets criteria for Hereditary Nonpolyposis colon CA (HNPCC)?
Annual colonoscopy starting at 20-25 yrs or 2-5 yrs prior to earliest age of CRC dx in family (whichever comes first)
When should you consider hereditary colon cancer syndromes?
- FH of CRC in > 1 family member
- PMH or FH of CRC at age < 50 yr
- PMH or FH of >10-20 adenomas
- PMH or FH of multiple extracolonic malignancies
