53. Colorectal cancer Flashcards
epidimiology ( age, persentage of family histolry )
- more patients are over 50
25% have family historu
risk factors
- adenomatous polys
- serrated polys
- familiar cancer syndromes
- inflammantory bowel disease
- tobacco use
- diet of processed meat with low fiber
location ( in order)
rectosigmoid> ascending > descending
presentantion ( according to location
right side bleeds, left side obstruct
Ascending –> exophitic mass, iron deficiency anemia, weight loss
Descending –> infiltrating mass ( napkin ring) , partial obstruction , colicky pain, hematochezia
microbe associated with colorectal cancer
rarely, bactermia with S. bovis
whent os uspect colorectal CA
iron deficiency anemia in males over 50 and postmenopausal females
clorectal cancer - screening
screen patients over 50 with
- colonoscopy
- flexible sigmoidoscopy
- fecal blood test
- fecal DNA test
the stool DNA test is a noninvasive laboratory test that identidies
DNA changes in the cells of a stool sample –> specifically looks for DNA alterations associated with colon polyps and colon cancer
barium enema x-ray
: apple core” lesion
markers / characteristcis
CEA tumor marker –> food for monitoring recurrence, should not used for screening
• A patient is diagnosed with right-sided colon cancer. What type of symptoms would you observe in this patient to reach your diagnosis?
An exophytic mass, iron deficiency anemia, weight loss
• Name at least three risk factors for colorectal cancer.
Adenomatous and serrated polyps, familial cancer syndromes, IBD, tobacco use, diet of processed meat with low fiber
• How do you screen for colorectal cancer?
Colonoscopy, flexible sigmoidoscopy, or stool occult blood testing
• A patient with past history of colorectal cancer is constantly monitored for recurrence. What nonspecific serum tumor marker is used?
Carcinoembryonic antigen (CEA)
• A man has fevers, hypotension, and a new murmur. Blood cultures grow a streptococcal species. Why might you want to perform a colonoscopy?
Although rare, colorectal cancer can be associated with Streptococcus bovis bacteremia (this patient may need a colonoscopy once stabilized)
• A male patient with iron deficiency anemia is concerned about colon cancer risk. Should he be concerned? Who else should be concerned?
Yes, as iron deficiency anemia can be a presenting sign of colorectal cancer, from occult GI bleeding; postmenopausal females
• Put in order (from most to least common) where colorectal cancer presents: descending colon, ascending colon, rectosigmoid junction.
Rectosigmoid junction, ascending colon, descending colon
• A man is worried about colon cancer. He wants a screening CEA level drawn, because he is “scared of colonoscopies.” What do you tell him?
CEA levels cannot be used for screening—they can be used only to monitor for recurrence in previously diagnosed patients
