Colorectal Cancer Flashcards
Colorectal cancer risk factors (7)
- Over 50 years
- Family history of CRC
- Personal history of colonic polyps (adenomas)
- Smoking
- Red meat and processed sugar consumption
- IBD
- Familial syndromes
Clinical presentation of CRC: right-sided
Cecum (wide, no obstruction)
- Bleeding
- Iron deficiency anemia
- Weight loss
Clinical presentation of CRC - left-sided
Recto-sigmoid (obstruction)
- Hematochezia
- Pencil stools
Colicky abdominal pain
Screening recommendations for CRC
In individuals over 50, FIT test every 2 years OR colonoscopy every 10 years
Screening for CRC in patients with IBD
Screening should start 8 years after onset of IBD. Colonoscopy every 1-2 years.
Diagnostic modality of choice for CRC
Colonoscopy
What can help with staging of CRC?
Abdominal CT
X-ray sign of CRC
Apple core lesion of barium enema
CRC treatment (3)
- Colectomy
- Chemotherapy
- Pelvic radiation
Name 2 familial hereditary syndromes that can predispose patients to CRC
- FAP: Familial adenomatous polyps
- HNPCC: Hereditary non-polyposis
What type of mutations are FAP and HNPCC?
Both are autosomal dominant.
FAP: mutations of APC gene
HNPCC: mutations of mismatch-repair genes
Number of polyps: FAP vs HNPCC
FAP: thousands of polyps
HNPCC: few polyps
Location: FAP vs HNPCC
FAP: distal colon or pancolonic
HNPCC: proximal colon
FAP treatment (and why)
Prophylactic colectomy (otherwise 100% of affected patients will develop CRC before the age of 45)
HNPCC prognosis
These patients will get cancer earlier than the general population. They will also be predisposed to cancer in other locations.
