Colon Caner Flashcards
What the second most important molecular pathways associated with colon cancer?
Microsattalite instability
MS: repeating sequences in DNA that are copied in cell division; mutation in DNA repair enzyme means you can’t maintain the DNA replication exactly and the microsats become unstable
Leads to mutations in other genes MSH2 and MLH1
Ex: HNPCC
HNPCC
Inherited mutation in DNA mismatch repair enzyme
De nova tumor (not adenoma to carcinoma) that arises at a young age, usually right sided
Increased risk of colorectal, ovarian, and endometrial carcinoma
Populations with an increased risk of colorectal carcinoma
Ulcerative colitis patients (chronic inflammation)
Putigier syndrome patients
Screening for colorectal cancer
Colonoscopy
Fecal occult blood testing
Begins at 50
Remove adenomatous polyps before carcinoma develops and detect cancer early (before it presents clinical symptoms)
Left sided carcinoma
Napkin ring lesion (circular growth around the colon)
Decreased stool caliber “pencil thin stool”
LLQ pain
Blood streaking in stool
Adenoma carcinoma sequence more common cause
Right sided colon cancer
Grows as a raised lesion, larger caliber so doesn’t result in obstrution
Iron deficiency anemia
Vague pain
More commonly associated with microsatalite sequence
Colonrectal cancer increases the risk for what infection?
Streptococcus bovis endocarditis
Endocarditis, strep bovis, test for colorectal carcinoma
Staging for colorectal carcinoma
Most important are depth of invasion (T) and spread to lymph nodes (N)
What is spread of colorectal cancer
Liver
What is the tumor marker for colorectal cancer?
CEA
Useful for looking at treatment response
Useful to detect recurrence
Not good for screening
What is the most common molecular pathway for colonic carcinoma?
Adeno-carcinoma sequence that begins with an APC mutation and then acquires other mutations
Seen with Familial Adematous Polyposis
