EOR GI part 6- colorectal CA Flashcards
What is colorectal carcinoma?
Adenocarcinoma of the colon or rectum
What is the incidence of colorectal carcinoma?
Most common GI CA
2nd most common Ca in the US
Incidence increases with age starting at 40 and peaks at 70-80 yrs
How common is colorectal carcinoma as a cause of CA deaths?
2nd most common cause of CA deaths
What is the male: female ratio of colorectal CA?
~1:1
What are the dietary RFs of colorectal CA?
Low-fiber, high-fat diets correlate with increased rates
RFs of colorectal CA: genetic
FHx
- FAP
- Lynch syndrome
RFs of colorectal CA: IBD
Ulcerative colitis>Crohn’s dz
Age
Previous colon CA
What is Lynch syndrome?
HNPCC- Hereditary NonPolyposis Colon Cancer
Autosomal dominant inheritance of high risk for development of colon CA
What are the current ACS recommendations for polyp/colorectal screening in asymptomatic pts without family (first-degree) hx of colorectal CA?
Starting at age 50, at least one of the following test regimens is recommended:
- Colonoscopy every 10 yrs
- Double contrast barium enema (DCBE) every 5 years
- Flex sigmoidoscopy every 5 years
- CT colonography every 5 years
What are the current recommendations for colorectal CA screening if there is hx of colorectal CA in a first-degree relative <60 yo?
Colonoscopy at age 40, or 10 years before the age at dx of the youngest first-degree relative, and every 5 yrs thereafter
What s/sx are associated with right-sided lesions?
R side of bowel has a large luminal diameter, so a tumor may attain a large size before causing problems Microcytic anemia Occult/melena more than hematochezia PR Postprandial discomfort Fatigue
What s/sx are associated with left-sided lesions?
L side of bowel has smaller lumen and semisolid contents Change in bowel habits (small caliber stools) Colicky pain Signs of obstruction Abdominal mass Heme pos or gross red blood Nausea Vomiting Constipation
What is the incidence of rectal CA?
Comprises 20-30% of all colorectal CA
What are the s/sx of rectal CA?
MC sx is hematochezia or mucus Also: Tenesmus Feeling of incomplete evacuation of stool Rectal mass
What is the DDx of a colon tumor/mass?
Adenocarcinoma Carcinoid tumor Lipoma Liposarcoma Leiomyoma Leiomyosarcoma Lymphoma Diverticular dz Ulcerative colitis Crohn's Polyps
Which diagnostic tests are helpful for colorectal CA?
Hx and PE Heme occult CBC Barium enema Colonoscopy
What dz does microcytic anemia signify until proven otherwise in a man or postmenopausal woman?
Colon CA