gastrointestinal cancer Flashcards
list the common cancers of the gastrointestinal system
oesophageal, pancreatic and colon
2 types of oesophageal cancer
oesophageal cancer:
- adenocarcinoma (from metaplastic columnar epithelium, lower 3rd of oesophagus, related to acid reflux, more developed world)
- squamous cell carcinoma (from normal oesophageal squamous epithelium, upper 2/3rd, acetaldehyde pathway, less developed)
explain clinical features
asymptomatic (incidental anaemia)
change in bowel habit (diarrhoea, constipation)
blood in stool
acute intestinal obstruction
give examples of investigations
Abdominal X-ray CT scan Barium enema colonoscopy CT virtual colonoscopy
pros and cons of AXR
abdominal X Ray
pros:
- cheap
- easy
- quick
not that useful though:
- sensitivity for obstruction
- specificity for obstruction
pros and cons of CT
pros:
- easy
- quick
- see large lesions
cons:
- may miss smaller lesions
- no tissue
- no therapy
Risk factors for colon cancer
Risk factors for colon cancer Family History Specific inherited conditions FAP, HNPCC, Lynch Syndrome Uncontrolled Ulcerative Colitis Age Previous Polyps
outcome for pancreatic cancer
Often referred to as the ‘silent killer’ as diagnosis is often very late. Generally, the outcome is poor and only 20% are suitable for a resection. Surgery is curative in 20-25% of cases; 1-year survival 18%, and 5-year survival 2%. Early symptoms include depression, abdominal pain and glucose intolerance. Subsequent advanced symptoms include weight loss, jaundice, ascites and gall bladder obstructions.
risk for pancreatic cancer
Risk factors Smoking Drinking Obesity Family Especially rare conditions such as MEN
Colon cancer epidemiology
More than 30,000 new cases per year 1 case per GP per year 14% of cancer in men, 12% in women 1 in 25 lifetime risk 1 in 50 risk of dying from CRC
development line of squamous cell carcinoma
Normal epithelium
Metaplasia - development of abnormal squamous cell
Dysplasia - proliferation of abnormal cells
Severe dysplasia - almost all cells are abnormal
Development of squamous cell carcinoma
Metastitsis
development line of adenocarcinoma
Normal epithelium Hyperplasia - abnormal proliferation of epithelial cells Development of adenomatous polyps Development of adenocarcinoma Metastasis
symptoms of oesophageal cancer
Symptoms do not usually appear until a >50% of the circumference of the oesophagus is cancerous. This is due to the tumour narrowing the tube.
Difficulty and pain when swallowing
Weight loss - due to lack of nutrition
Pain in the breast bone and stomach, or a feeling of reflux
In later stages, further symptoms include:
Nausea, vomiting, and regurgitation of food
Vomiting blood, due to trauma to the tumour
