0316 - Upper GIT Malignancies Flashcards
Discuss the demographics of oesophageal cancer.
Very common worldwide, less so in western countries, with marked geographic and ethnic variation.
Incidence rises with age, and increasing in Australia.
Discuss the risk factors of oesophageal cancer.
Low SES
Alcohol, smoking, obesity, reflux, Barrett’s metaplasia
Injury (thermal/radiation)
Toxins
Dietary deficiencies
Genetic/hereditary risks
Discuss the pathology of oesophageal SCC.
SCC much more common than adeno, but adeno rising.
Multi-step carcinogenesis.
Can be fungating or ulcerating.
Presence of ‘keratin pearls’ demonstrates that it’s squamous.
Discuss the pathology of oesopageal adenocarcinoma.
Less common than SCC, but rising (Barrett’s)
Typically arise at GOJ (Barrett’s), may be difficult to distinguish from proximal gastric cancer.
Follows dysplasia-carcinoma sequence, suitable for surveillance and hopefully preventable with PPIs.
Presence of goblet cells indicates that it’s intestinal metaplasia.
Discuss the treatment of oesophageal cancer.
Radiotherapy for SCC, chemo for adenocarcinoma.
Surgery for both.
5-year survival stage I = 95%, stage IV =<1yr median
Discuss the behaviour of oesophageal cancer.
Mets to liver, lung, adrenal gland, kidney, and bone.
Discuss the demographics of gastric cancer.
Second most common tumour worldwide.
Associated with H. Pylori, so more common in developing countries and Japan.
Highly lethal - presents late with limited treatment options.
Discuss the risk factors of gastric cancer.
H. Pylori infection
Autoimmune gastritis
Diet (nitrosamines, slat, low fruit/veg)
Tobacco
Radiation
Some surgeries (gastroenterostomy)
Genetics (H. Pylori suscetibility, familial gastric cancer, HNPCC/Lynch)
Discuss the pathology of gastric cancer.
Adenocarcinoma - can be intestinal or diffuse
Many shared aberrations, e.g. p53
Progressive from gastritis, metaplasia, cancer
Discuss the treatment of gastric cancer.
Surgery for curative intent, chemo for palliative
Intestinal type mets to liver, diffuse type to ovaries, both to peritonium
5 Year survival - Stage I - 95%, stage IV - 7%
Discuss the behaviour of gastric cancer. (Where does it Metastasize to?)
Intestinal type mets to liver,
diffuse type to ovaries,
both to peritoneum
Discuss the demographics of small bowel cancer.
Uncommon - most are mets from elsewhere.
Discuss the risk factors of small bowel cancer.
Other cancer metastasising.
Discuss the pathology of small bowel cancer.
Adenocarcinoma, commonly in the ampulla.
Adenoma/carcinoma elsewhere - could be polyposis
Discuss the prognosis of small bowel cancer.
Poor prognosis as typically present late
Palliative treatment
Discuss the demographics of gastrointestinal stromal tumours (GIST).
Commonest mesenchymal GI tumour
Commonest in 40-60yr old males.
Genetic links
Discuss the histology of gastrointestinal stromal tumours (GIST).
Spindled or epithelioid cells in the submucosa
Discuss the molecular genetics of gastrointestinal stromal tumours (GIST).
80-85% have gain of function KIT mutations, which abnormally activate a gene, activating cell proliferation and survival pathways.
Others are wild-type or have PDGFRA mutations.
Discuss the management of gastrointestinal stromal tumours (GIST).
Targeted therapy with Imatinib.
Binds to ATP binding pocket, preventing substrate phosphorylation and thus inhibiting proliferation and survival.
What is metaplasia?
A reversible change in which one adult cell type is replaced by another - e.g. change from squamous to columnar epithelium.
What is dysplasia?
Disordered growth, characterised by pleomorphism, hyperchromatism, and loss of normal orientation.
