45. Molecular Pathogenesis and Precision Medicine Flashcards
What are the risk factors for bowel cancer?
Age, poor diet, obesity
Smoking, excess alcohol
Family history (FAP, HNPCC)
What are the symptoms of bowel cancer?
Changes in bowel movements Abdominal discomfort/bloating Loss of apetite/weight loss Blood in stool Unexplained anaemia/fatigue 'Pencil stools' Pelvic pain
What is Vogelstein’s theory of colonic carcinogenesis?
Different genetic changes are associated with progression of benign tumours to malignant ones
More than one somatic mutation is needed to produce a full cancer cell
What 3 things are used to stage bowel cancer?
Size of tumour
Lymph nodes
Metastases
What is stage 1 of bowel cancer?
Tumour is in inner wall of colon or rectum only
What is stage 2 of bowel cancer?
Tumour is in muscle layer of colon or rectum
May have spread to other tissues
What is stage 3 of bowel cancer?
Tumour spread to nearby lymph nodes
What is stage 4 of bowel cancer?
Tumour has spread to other parts of the body
What is the difference between a colonoscopy and a sigmoidoscopy?
Colonoscopy examines entire length
Sigmoidoscopy examines only the lower third
What does it mean if a tumour is sessile?
No stalk present
What does it mean if a tumour is pedunculated?
Attached to the surface by a stalk
What is the difference between familial and hereditary colon cancer occurance?
Familial: occurs in more than one family member could be genetic, non-genetic or multifactorial
Hereditary: exact gene defect is known
What is APC?
Tumour suppressor gene
Mutated in large number of sporadic and inherited colon cancers
Normally decreases beta-catenin
What is the inheritance of a mutated APC allele called?
Familial adenomatous polyposis
What is HNPCC?
Hereditary Nonpolyposis Colorectal Cancer
Only small number or no polyps present
Inherited mutation in a DNA mismatch repair gene
