GI Flashcards
third most common cancer in US men
crc
third most common cancer in us women
crc
what kind of cancer gives rise to crc
virtually always adenomas – endoluminal adenocarcinomas
rarely carcinoid, lymphoma, kaposi sarcoma
5 screening tests for crc
+1 for monitoring
fobt dre colonoscopy flexible sigmoidoscopy barium enema cea carcinoembryonic antigen
sn and sp and ppv of fobt for crc?
sn sp poor
ppv ~20%
if positive get colonoscopy
what % crc palpable by dre?
~10%
what is the most sn and sp test for crc
colonoscopy
diagnostic test of choice following +fobt
colonoscopy
is colonoscopy diagnostic or therapeutic?
both
biopsy
polypectomy
what % of polyps and cancers can be reached by flexible sigmoidoscopy?
50-70%
how long is the flexible sigmoidoscope
60 CM
is a flexible sigmoidoscopy longer or shorter than a colonoscope
shorter 60 CM only needs to reach sigmoid which is distal
flexible sigmoidoscopy his diagnostic in roughly what percentage of CRC’s
two thirds
when is barium enema used to screen for crc
to eval entire colon, complementary to flex sigmoidoscopy
if abnormal finding on barium enema what is next step
colonoscopy
True or false carcinoembryonic antigen CEA is useful for screening
false
use for establishing a baseline, monitoring treatment efficacy, surveilling for recurrence
T/F CEA carcinoembryonic antigen has prognostic significance for crc
T
Preoperative CEA >5 NG/ML has worse prognosis
how is colorectal cancer clinically staged
CT scan chest abdomen pelvis
Physical exam ascites hepatomegaly lymphadenopathy
describe for patterns of colorectal cancer spread
Direct extension – circumferential then through the wall to invade other abdominoperineal organs
Hematogenous – portal circulation to liver, lumbar/vertebral veins to lungs
lymphatic - regionally
Transperitoneal and intraluminal
what is the most common sight of distant spread of crc
liver
how does colorectal cancer spread to the lungs
Hematogenously via lumbar and vertebral veins
T/F
All CRC’s bleed all the time
F
Some bleed intermittently some not at all
at what age does colon cancer screening begin
age 50 is standard
Begin at age 40 if one family history of colon cancer, or 10 years before onset of family member
what % CRC presents already with mets
~20%