Colon Polyps and CRC

How is CRC screened>

FOBT
FIT
Stool DNA
Flexible Sigmoidoscopy
CT colongraphy
Colonscopt

Fecal Occult Blood Test (FOBT)

test to detect occult blood in feces

What foods can affect a FOBT

Red meat
Horseradish
Broccoli

What medications should be d/c prior to FOBT

ASA and NSAIDs (7 days)
Vitamin C (2days_

Fecal Immunochemical Test (FIT)

uses antibodies to detect globin a protein removed from heme which is present exclusively in the lower intestine

What are the benefits to using FIT instead of FOBT

No dietary or med restrictions
Only one sample instead of 3

What is important patient education with performing a FIT

Delay in sending sample can cause a false negative

Stool DNA test

A test that looks for abnormal neoplastic cells in stool

What can be detected on stool DNA test

High Grade Adenomatous Polyps
Colonic Malignancy

How should a patient prep for CT colongraphy

Clear Liquids x 24 hours
Bowel prep

CT Colongraphy

A CT imaging of the colon as it is filled with CO2 via thin rectal catheter

What are contraindications to CT colongraphy

Acute Colonic Inflammation
Diverticulitis
CR Surgery
Recent Bx
Bowel Obstruction
Bowel perforation

What is the bowel prep for sigmoidoscopy imaging

Two Sodium Phosphate Enemas the morning of

How fare can a flexible sigmoidoscopy see

60 cm

What is the gold standard for CRC screenings

Colonscopy

What are the drawbacks to colonscopy

Needs good prep
Needs anesthesia and transport
Needs to hold anticoagulatants

What is the CRC screening for asymptomatic average risk adults (ACS)

• Annual FOBT or FIT
• Stool DNA every 3 years
• CT colonography or Sigmoidoscopy every 5 years
• Colonoscopy every 10 years

When should we screen the average patient for CRC? (ACS_

45-75 = Definite
76-85 = Elective

When should we screen the average patient for CRC? (USPSTF)

45-49 (B)
50-75 (A)
76-85 (C)
None > 85

What is the CRC screening for asymptomatic average risk adults (USPSTF)

• Annual FOBT or FIT
• Stool DNA every 1-3 years
• CT colonography or Sigmoidoscopy every 5 years
• Colonoscopy or Sigmoidoscopy (If FIT testing annual) every 10 years

Who are considered high risk for CRC

FH of first degree or two second degree
Colon Polyps
Colon Cancer
IBD
Strep Gallolyticus

What is the only screening used in high risk CRC patient

Colonoscopy every 5 years

When are high risk CRC patients screened?

Age > 10
10 years before youngest CRC diagnosis

What is the bowel prep for colonoscopy

◦ Miralax with bisacodyl
(controversial) +
Gatorade/Powerade

Strep gallolyticus

A bacteria that often endocarditis and bacteremia
Risk factor of CRC

Colon Polyps

a protuberance of tissue into the lumen above the surrounding colonic mucosa

Tenesumus

a continual or recurrent inclination to evacuate the bowels, caused by disorder of the rectum or other illness.

What are the types of colon polyps

Inflammatory
Hamartomatous
Serrated
Adenomatous

Adenomatous Polyps

A common type of colon polyp that tendsto be asymptomatic

How are adenomatous polyps classifeid

Appearance
Histology

What are the appearance types of adenomatous polyps

◦ Pedunculated (stalked)
◦ Flat
◦ Depressed
◦ Sessile (flat based)

What are the histo types of adenomatous polyps

Tubular - 80% of polyps are this type
◦ Villous - 5-15%
◦ Tubulovillous - 5-15%

What types of adenomatous polyps most often causes CRC

Sessile Villous

What are risk factors for adenomatous polyps

◦High fat diet
◦Diet high in red meat
◦Low fiber diet
◦Smoking
◦Obesity
◦Older age
◦Male sex

What should be don if sigmoidoscopy visualizes a adenomatous polyps

Colonscopy

What are considered high risk adenomatous polyps

3 or more
TA > 10 mm
Histo = Villous
High Grade Dysplasia

How often should colonscopy be done for adenomatous polyps

3-5 years

Familial Adenomatous Polyposis (FAP)

An autosomal dominant trait resulting in the development of polyps and benign growths in the colon. Polyps often develop into malignant growths and cause cancer of the colon and/or rectum.

When do we start screening patients with FAP

Age 10-12

How do we screen a patient with FAP

Yearly Sigmoidoscopy

What is the tx for FAP?

• NSAIDs and Celecoxib temporary decrease
• Total Colectomy

Lynch Syndrome / Hereditary Non-Polyposis Colorectal Cancer (HNPCC)

An autosomal dominant trait resulting in CRC and endometrial carcinoma

How will HNPCC form

Early onset (48)
Right Sided

3-2-1 Rule

A way to remember the Amsterdam II criteria for Lynch syndrome dx

• 3 or more relatives with Lynch associated cancers
• 2 generations of Lynch associated cancers
• 1 cancer was dx before 50

How does right sided / cecal CRC present

• Chronic, insidious blood loss without a noticeable change in the stool color
• Fatigue
• Palpitations
• Iron Deficiency Anemia

How does left-sided CRC presetn

Obstruction
Abdominal Cramping

Apple Core Lesion

A XR finding where the large bowel looks like an apple core
Sign of left CRC

How does Rectosigmoid CRC present

◦Hematochezia
◦Tenesmus
◦Narrow stool, ribbon stool
◦Anemia

How do we stage CRC

TNM Staging

How does CRC often spread

Lymph Nodes
Portal Venous System

What is the common spread site of CRC

Most cases = Liver
Distal Rectal = Lungs (bypasses portal system)

What is the tumor marker for CRC

CEA (carcinoembryonic antigen)

What can cause elevated CEA

CRC (!)
Gastritis
PUD
Diverticulitis
Liver Disease
COPD
DM
Inflammatory