Week 4: GI Cancer Flashcards
Cancer in the mouth, esophagus, pharynx, salivary glands is typically caused by what?
Not usually hereditary and caused my smoking and tobacco
T/F there is many forms of inherited liver cancer
False! Typically not inherited, primary liver cancer is rare
However common site of metastasis
How common are gallbladder and small intestinal cancers?
Rare! But in some cases can be related to Lynch syndrome
Most anal cancers are due to what?
Most anal cancers due to infection and not hereditary
Brief description of function of the stomach, small intestine, and large intestine in digestion.
-Stomach: churns food, produces gastric juices
-Small intestine: chyme and enzymes, bile breaks up fat, nutrients absorbed by small intestine
-Large intestine: water absorption, bacteria in colon fed on fiber and produce vitamins
Colon cancers affecting what demographic of people are more likely to develop in the right side/proximal colon?
-Women
-Younger patients historically
-Lynch syndrome patients
Colon cancers affecting what demographic of people are more likely to develop in the left side/distal colon?
-Men are more likely to develop distal colon and rectal cancer
-Increasing incidence of patients under age 50
Is a man with Lynch syndrome more likely to get right sided or left sided colon cancer?
Right side cancer because of Lynch
Cancer in what part of the colon is more common in Lynch syndrome?
Right/proximal
Why are tumors in the right/proximal colon less commonly diagnosed in earlier stages or are missed on colonoscopies?
-They can be missed if endoscopist doesn’t spend much time on right side since it is furthest from where colonoscopy starts
-If a tumor on the right side was bleeding, blood wouldn’t be seen in stool because it wouldn’t be apparent by time it got through rest of the colon
What is the gold standard for colon cancer screening?
-Colonoscopies!
-Other cancers don’t have screening like this available
-Overall adherence in the US is low
-Recent rise in young colon cancer has changed recommendation to start colonoscopy at 45yr instead of 50yr
What are some factors that contribute to low adherence to colonoscopies?
-Access to endoscopist
-Travel
-Need to care for others-recovery and need for ride home
-Unpleasant procedure
Briefly what is the difference between a flexible sigmoidoscopy and a virtual colonoscopy?
-Flexible sigmoidoscopy: physician examines bottom part of colon for polyps, sedation not always needed, bowel prep required
-Virtual colonoscopy: CT scan to inspect colon lining for polyps, bowel prep required
Brief difference between Fecal Immunochemical Test (FIT) and Cologuard?
-FIT: stool based test performed at home and sent to lab which looks for trace amounts of blood
-Cologuard: stool is collected at home and sent out for testing, study looks for blood or DNA markers associated with colon cancer
What are the three different categories/purposes for colonoscopies?
-Screening: no hx of cancer/precancerous lesions and no symptoms
-Surveillance: hx of CRC or polyps
-Diagnostic: symptoms concerning for CRC, possible tumors
Name the 4 types of noncancerous polyps
- Hyperplastic
- Submucosal
- Inflammatory: normal inflammation
- Harmartomatous: low malignant potential (depending on underlying syndrome may have greater potential)
What types of polyps are pre-cancerous?
-Traditional tubular adenomas: sessile or pedunculated, less than 5% will progress to carcinoma –but difficult to predict who is the 5%!
-Serrated polyps: more difficult to identify during colonoscopy, SSLs and TSAs can progress to cancer, 20-30% of CRC
If a patient has a seemingly normal colonoscopy but develops colon cancer a short time after, what is one possible explanation?
-The patient had precancerous polyps that were difficult to see on colonoscopy
-Therefore, they already had polyps but were not well visualized and resulted in seemingly quick development of colon cancer
What is the median age of diagnosis for CRC? What is the 5-year relative survival rate?
Avg age of diagnosis: 66yr
5yr survival: 65%
