Lecture 22 - Gastrointestinal cancers Flashcards
What are the hallmarks of cancer?
- Evasion of apoptosis
- Self-sufficiency in growth signals
- insensitivity to anti-growth signals
- Tissue invasion and metastasis
- Limitless replicative potential
- Sustained angiogenesis
What are the two types of oesophageal cancer?
SCC and ADC
What does ADC stand for?
Adenocarcinoma
What are the risk factors of ADC?
- Barrett’s metaplasia
- Gender
- Age
- Reflux
- Obesity
- H-pylori
- Anti-oxidants
What is the molecular architecture of oesophageal ADC development?
- Normal squamous epithelium
- Barrett’s metaplasia
- Dysplasia
- ADC
What is the most important risk factor of gastric factors?
Helicobacter pylori infection
H.Pylori infection in the antrum causes hypergastrinemia. and duodenal ulcers. This leads to reduced acid secretion and hypochlorhydria. This is largely associated with gastric ulcers.
What causes hereditary diffuse gastric cancer?
- HDGC is caused by gremlin mutations in the CDH1 gene.
- E-cadherin is thought to prevent the initial dissociation of epithelial cells from the original tumour mass, the mutation caused e-cadherin repression hence tumour.
What are the risk factors of colorectal cancer?
- Meat and fish - increase with intake of red and processed meat. Decrease with high intake of meat.
- Fibre - high fibre = lower risk
- Obesity - increased risk
What are the two types of colorectal cancer?
- Sporadic (80-90%)
- Familial (10%)
What is Familial adenomatous polyposis coli (FAP)?
- Multiple benign adenomatous polyps at an early age.
- Mutated APC gene on chromosome 5q21
- Prophylactic surgery.
What is the adenoma-carcinoma sequence (ACS) defined as?
A set of recurrent driver mutations in APC, KRAS, SMAD4 and TP53 genes, that accumulate during adenoma formation and progression to sporadic colorectal cancer (CRC), often correlating with specific stages of the developmental process.
