Cancer as disease-colorectal cancer:part 1 Flashcards
What does the colon do
Extraction of water from faeces ,Faecal reservoir ,Bacterial digestion for vitamins
What sort of gene is mutated in FAP?
TSG that controls cell growth
What is the main risk factor for colorectal cancer?
Poor diet
Explain lymph node importance in tumour classification and the importance of the apical lymph node
Lymphs drain fluid, which liquid tuours canbe found so lymph node presence is an significant mark for staging. Apical(near lumen_ lymph node is one of th last lymph node that is drained into(apical= near lumen), there if it is present there yuou now all the tumours below are affected . and there is signifant spread in lymph nodes
What features of diet increase colorectal cancer risk
Low fibre High fat Refined carbs
What type of tumour are the majority of colorectal cancers?
Adenocarcinomas (originated in glandular tissue)
How APC mutation contributes to cancer
APC mutation prevents cell loss mutation
Normally we have protective mechanisms to eliminate genetically defective cells by;
Natural loss
DNA monitors
Repair enzymes
What is an adenoma?
Benign tumour formed from glandular cells in epithelial tissues
Describe the boundaries of the colon
From iliocaecal valve to the rectume
Which type of adenoma commonly precedes colorectal cancer and what is the incidence of this type of adenoma?
Polyps 25% of adults have by 50 years
Recall the grades of Duke’s that can be assigned to a colorectal cancer and what each indicates
Dukes A: neg nodes, growth limited to muscularis propria Dukes B: neg nodes, EXTENDS beyond MP Dukes C1: POS nodes, neg apical lymph nodes upon removal Dukes C2: POS apical lymph nodes
give 3 types of polyps
Metaplastic/Hyperplastic
Adenomas
Juvenile
By what mechanism do Vit C and E protect against colorectal cancer?
Clear up free radicals
How is population-screening for colorectal cancer carried out?
Faecal occult blood for people with exceptionally high risk of getting the disease and fing ways for preventing thre disease.
What are the 3 main presentations of colorectal cancer?
- Change in bowel habit 2. PR bleeding 3. Iron-deficiency anaemia
