Cancer of the gut Flashcards
Cell cancers in the GI tract
Squamous -> Squamous cell carcinoma
Glandular -> Adenocarcinoma
Enterochromaffin -> Carcinoid tumours
Interstitial cells of Cajal -> Gastrointestinal stromal tumours
Smooth muscle -> Leiomyoma/Leiomyosarcoma
Adipose -> Lipoma
Two types of oesophageal cancer
Adenocarcinoma - from the metaplastic columnar epithelium, lower 1/3 of oesophagus, related to acid reflux, more developed world
Squamous cell carcinoma - from normal oesophageal squamous epithelium, upper 2/3, acetaldehyde pathway, less developed world
Progression of oesophageal cancer
Oesophagitis (inflammation) -> Barrett’s (metaplasia) -> Dysplasia -> Carcinoma (neoplasia)
Risk factors of colorectal cancer
Family history - specific inherited conditions (FAP, HNPCC, Lynch Syndrome)
Uncontrolled Ulcerative Colitis
Age
Previous Polyps
It is not a single gene process because there is a sequence of genetic errors (APC, K-ras, p53, 18q)
Symptoms of colorectal cancer
Asymptomatic (at the caecum)
Change in bowel habit: diarrhoea, constipation (diarrhoea is a much bigger concern)
Blood in stool
Acute intestinal obstruction
*Rectal bleeding with anal symptoms, abdominal pain in absence of obstruction and change in bowel habit to harder + less frequent stool IS NOT associated with colorectal cancer.
Pros and Cons of abdominal X-ray
Pros: cheap, easy, quick
Cons: not that useful - 77% sensitivity for obstruction and 50% specificity for obstruction
Pros and Cons of plain CT scan
Pros: easy, quick, see large lesions
Cons: may miss smaller lesions, no tissue, no therapy
Pros and Cons of barium enema
Pros: reasonable sensitivity and specificity
Cons: time intensive, technically demanding, unacceptable to patients - so it’s hardly used anymore
Pros and Cons of colonoscopy
Pros: safe, relatively quick, high sensitivity, able to obtain tissue
Cons: BOWEL PREP (to clear rectum) - 2 days of iatrogenic diarrhoea, small risk of perforation and dehydration
Pros and Cons of CT virtual colonoscopy
Pros: quick, easy, reduced bowel prep is more tolerable, as good as colonoscopy for lesions
Cons: unable to obtain tissue, unable to remove lesions
Symptoms of pancreatic cancer
Silent killer - non specific symptoms
(A new) Virchow’s Triad = pain 70%, anorexia 10%, weight loss 10%
Early symptoms: abdominal pain, depression, glucose intolerance
Late symptoms: weight loss, jaundice, ascites, obstructed gall bladder
Risk factors of pancreatic cancer
Smoking, drinking, obesity, family
Treatment for pancreatic cancer
PANCREATIC CANCER HAS A POOR OUTCOME
Only 20% are suitable for a resection and surgery is curative in 20-25% of cases
