Alimentary System 14 - GI cancer Flashcards Preview

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Flashcards in Alimentary System 14 - GI cancer Deck (29)
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1
Q

Where does bowel cancer place in causes of cancer death?

A

2nd most prevalent

2
Q

Where does bowel cancer place in the most common cancers?

A

4th most common after prostate cancer

3
Q

Which cancers can occur in epithelial cells?

A
  • Squamous epithelia form squamous cell carcinomas

- Glandular epithelium form adenocarcinomas

4
Q

List the cancers that can occur in neuroendocrine cells

A
  • Enterochromaffin cells form carcinoid tumous

- Interstitial cells of cajal form gastrointestinal stromal tumours

5
Q

List the cancers that can occur in connective tissue

A
  • Smooth muscle leiomyoma/ leiomyosarcomas

- Adipose tissue forms lipomas

6
Q

What do you need to ask when a patient comes to you with difficulty swallowing (dysphagia)?

A
  • How long
  • What foods cant you swallow
  • Any vomiting
  • Any other symptoms
  • Look at risk factors
7
Q

What two cancers can form in the oesophagus?

A
  • Adenocarcinomas

- Squamous cell carcinomas

8
Q

Where do adenocarcinomas form in the oesophagus and why?

A
  • Formed from metaplastic columnar epithelium
  • Affect the lower 1/3 of the oesophagus, related to acid reflux
  • More developed world
9
Q

Where do squamous cell carcinomas from in the oesophagus and why?

A
  • In the upper 2/3 of the oesophagus
  • From normal oesophageal squamous epithelium
  • Acetaldehyde pathway (related to alcohol)
  • Less developed world
10
Q

What would you do if you expected a patient had oesophageal cancer?

A

Endoscopy, where what looks like a river of shiny red oesophagus would be seen due to the acid and barretts oesophagus (columnar cells)

11
Q

Describe the progression from reflux to cancer

A
  • Inflammation in the oesophagus (oesophagitis)
  • Barretts metaplasia
  • Dysplasia
  • Carcinoma
12
Q

List the risk factors for bowel cancer

A
  • Family history
  • Inherited conditions (FAP, HNPCC, lynch syndrome)
  • Uncontrolled ulcerative colitis
  • Age
  • Previous polyps
13
Q

What form of cancer is seen in the bowel?

A

Adenocarcinoma

14
Q

Describe the pathology of bowel cancer

A
  • Not a single gene process
  • Sequence of genetic errors (APC, K-ras, p53, 18q)
  • APC+COX2 result in hyperproliferative endothelium and small adenoma formation
  • K-ras results in large adenoma
  • p53 and loss of 18q result in colon carcinoma
  • Inheritence is not simple mendelian
15
Q

List the causes of bowel cancer

A
  • Aspirin
  • Folate
  • Calcium
  • Oestrogen
16
Q

List the symptoms of bowel cancer

A
  • Can be asymptomatic with incidental anaemia
  • Change in bowel habit (diarrhoea/constipation)
  • Blood in stool
  • Acute intestinal obstruction
17
Q

List bowel symptoms not associated with colorectal cancer

A
  • Rectal bleeding with anal symptoms (itch, soreness/ discomfort, lump, prolapse)
  • Change in bowel habit to harder or less frequent stool
  • Abdominal pain in the absence of obstruction
18
Q

How could you investigate a patient with suspected colorectal cancer?

A
  • Abdominal x-ray
  • CT scan
  • Barium enema
  • Colonoscopy
  • CT virtual colonoscopy
19
Q

List the advantages and disadvantages of abdominal x ray in assessing colorectal cancer

A
  • Cheap
  • Easy
  • Quick
  • 77% sensitivity
  • 50% specificity
20
Q

List the pros and cons of a plain CT in assessing colorectal cancer

A
  • Quick
  • Easy
  • Can see large lesions
  • May miss smaller lesions
  • No tissue
21
Q

List the pros and cons of a barium enema

A
  • Good sensitivity and specificity
  • Time intesive
  • Technically demanding
  • Unacceptable to patients
22
Q

List the pros and cons of colonoscopy

A
  • Safe
  • Relatively quick
  • High sensitivity
  • Can obtain tissue
  • Requires 2 days of diarrhoea, with risk of dehydration
  • Small risk of perforation (<1:2000)
23
Q

Describe the process of CT virtual colonoscopy

A
  • Modified bowel prep (reduced)
  • Stools are tagged using bismuth
  • Computer aided subtraction is used to create images
24
Q

List the pros and cons of CT virtual colonoscopy

A
  • Quick
  • Easy
  • Reduced bowel prep
  • As good as colonoscopy for lesions >6mm
  • Unable to obtain tissue or remove lesions
25
Q

List the three factors commonly seen in pancreatic cancer

A
  • Non specific symptoms
  • Pain (70%)
  • Anorexia (10%)
  • Weight loss (10%)
26
Q

List the early symptoms of pancreatic cancer

A
  • Abdominal pain
  • Depression
  • Glucose intolerance
27
Q

List the late symptoms of pancreatic cancer

A
  • Weight loss
  • Jaundice
  • Ascites
  • Obstructed gall bladder
28
Q

List the outcomes for pancreatic cancer patients

A
  • 20% suitable for resection
  • Surgery curative in 20-25% of cases
  • 1 year survival 18%
  • 5 year survival 2%
29
Q

List the risk factors for pancreatic cancer

A
  • Smoking
  • Drinking
  • Obesity
  • Rare conditions such as MEN