Gastric Cancer and Inflammatory Bowel disease

Question 1

Gastric carcinoma

Answer 1

• poorly diagnosed. Low incidence high mortality
• no refrigerators in 1930s resulted in high intake of salted/ preserved
  Meats, containing nitrites and nitrosamines
• staple diet in smoked foods (3,4 benzopyrene)
• helicobacter pylori - pernicious anaemia (B12 deficient), chronic inflammation, Metaplasia, dysplasia, carcinoma

Question 2

Subtypes of gastric carcinoma

Answer 2

Intestinal:

• glandular bulky lesion which protrudes into lumen of the stomach due to food intake. Decreasing in incidence due to better diet now from then.
• nausea, vomiting blood, blood in stool
• spreads: lymphatics, across the wall and drop and seed through gravity onto organs further down the cavity

Diffuse:

• infiltrative
• poorly differentiated

Question 3

IBD: Crohn disease epidemiology

Answer 3

• idiopathic
• female, young
• abnormal immune response against own bacteria, formation of inflammatory response against intestine. May also be due to particular genes
• occurs in small and large Bowel

Question 4

Characteristics of Crohn’s disease

Answer 4

• skip lesions: normal piece of bowel, lesion, normal piece of bowel
• cobblestone appearance- due to scarring. Sections which are chronically inflamed. Contains fissures which is splitting of mucosa causing bleeding.
• infections are common
• presence of granulomas which leads to giant cells
• fissures- fistula linking up inflammation from piece of bowel to another organ.
• strictures- narrowing of Lumen due to scarring
• malabsorption leading to diarrhoea (bloody)
• increased cancer transformation (large bowel)
• systemic- can impact on joints, skin

Question 5

Ulcerative colitis epidemiology

Answer 5

• idiopathic
• equal gender
• young
• mutations of multiple genes.. HLA association?
• only affects large bowel
• usually impacts rectum and left colon
• ulceration of colonic mucosa
• characteristic lesions called pseudo polyps- growth which protrudes into the lumen of a vessel. Island or normal mucosa surrounded by sea of ulcers.
• clinically: bloody mucoid diarrhoea
• cancerous transportation - Crohn’s
• also effects other tissues such as joints, skin

Question 6

Diverticular disease

Answer 6

• diverticulums in large bowel. Similar to aneurysms. Weakening where blood vessels enter and there is no smooth muscle.
• faecal matter can get caught in diverticulum which may cause bacterial infection, Rupture and leakage into other areas

Question 7

Colonic tumours

Answer 7

Hyper plastic polyps: no cancer transformation
Adenonatous polyps: gland like tumours.
- tubular (many pedunctulated- on a stalk)- the bigger it is, the more the chance of cancer. Hyperchromasia- nuclei are changing, increasing in depth of nuclei, signified by a dark stain, are malignant.
- Villous- (cauliflower looking)- less common but life threatening. Extremely large, usually always malignant. Sessile lesion (flat)
- tubulovillous - mixture of both

Familial polyposis syndromes run in families on APC gene

Question 8

Colonic tumour carcinoma

Answer 8

Incidence stable, mortality going down
Lower in Japan- less red meat
Higher in men
Peaks about 55
Diet due to: decreased fibre intake, high animal fat diet, high refined carb diet, increased transit time prevents carcinogens from acting on mucosa, differences in bacteria of vegetarians and meat eaters
- genetics: adenoma- carcinoma sequence- series of mutations of various genes over a number of years
- metastasis to the liver