0316 - Upper GIT Malignancies

Question 1

Discuss the demographics of oesophageal cancer.

Answer 1

Very common worldwide, less so in western countries, with marked geographic and ethnic variation.
Incidence rises with age, and increasing in Australia.

Question 2

Discuss the risk factors of oesophageal cancer.

Answer 2

Low SES

Alcohol, smoking, obesity, reflux, Barrett’s metaplasia

Injury (thermal/radiation)

Toxins

Dietary deficiencies
Genetic/hereditary risks

Question 3

Discuss the pathology of oesophageal SCC.

Answer 3

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.

Question 4

Discuss the pathology of oesopageal adenocarcinoma.

Answer 4

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.

Question 5

Discuss the treatment of oesophageal cancer.

Answer 5

Radiotherapy for SCC, chemo for adenocarcinoma.

Surgery for both.

5-year survival stage I = 95%, stage IV =<1yr median

Question 6

Discuss the behaviour of oesophageal cancer.

Answer 6

Mets to liver, lung, adrenal gland, kidney, and bone.

Question 7

Discuss the demographics of gastric cancer.

Answer 7

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.

Question 8

Discuss the risk factors of gastric cancer.

Answer 8

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)

Question 9

Discuss the pathology of gastric cancer.

Answer 9

Adenocarcinoma - can be intestinal or diffuse

Many shared aberrations, e.g. p53
Progressive from gastritis, metaplasia, cancer

Question 10

Discuss the treatment of gastric cancer.

Answer 10

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%

Question 11

Discuss the behaviour of gastric cancer. (Where does it Metastasize to?)

Answer 11

Intestinal type mets to liver,

diffuse type to ovaries,
both to peritoneum

Question 12

Discuss the demographics of small bowel cancer.

Answer 12

Uncommon - most are mets from elsewhere.

Question 13

Discuss the risk factors of small bowel cancer.

Answer 13

Other cancer metastasising.

Question 14

Discuss the pathology of small bowel cancer.

Answer 14

Adenocarcinoma, commonly in the ampulla.

Adenoma/carcinoma elsewhere - could be polyposis

Question 15

Discuss the prognosis of small bowel cancer.

Answer 15

Poor prognosis as typically present late

Palliative treatment

Question 16

Discuss the demographics of gastrointestinal stromal tumours (GIST).

Answer 16

Commonest mesenchymal GI tumour

Commonest in 40-60yr old males.

Genetic links

Question 17

Discuss the histology of gastrointestinal stromal tumours (GIST).

Answer 17

Spindled or epithelioid cells in the submucosa

Question 18

Discuss the molecular genetics of gastrointestinal stromal tumours (GIST).

Answer 18

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.

Question 19

Discuss the management of gastrointestinal stromal tumours (GIST).

Answer 19

Targeted therapy with Imatinib.

Binds to ATP binding pocket, preventing substrate phosphorylation and thus inhibiting proliferation and survival.

Question 20

What is metaplasia?

Answer 20

A reversible change in which one adult cell type is replaced by another - e.g. change from squamous to columnar epithelium.

Question 21

What is dysplasia?

Answer 21

Disordered growth, characterised by pleomorphism, hyperchromatism, and loss of normal orientation.