Colorectal cancer Flashcards
What are the risk factors for colorectal cancer?
Age Male Previous adenoma or colorectal cancer Diet Obesity Lack of exercise Smoking Diabetes
How do most colorectal cancers arise?
Pre-existing colorectal polyps
What is the origin of adenoma polyps?
Epthelial
What are the 2 min histological types of adenomas?
Tubular
Villous
What is the morphology of adenoma polyps?
Pedunculated
Sessile
How does colorectal cancer present?
Rectal bleeding Altered bowel opening Diarrhoea Iron deficiency anaemia Palpable rectal or right lower abdominal mass Acute colonic obstruction Weight loss
What are the investigations of colorectal cancer?
Colonoscopy (retrieve tissue biopsy, polypectomy)
Barium enema
CT colonography
What are the risks of colonoscopy?
Perforation
Bleeding
Sedation issues
What is the pathway progression of Duke’s classification?
A= tumour confined to mucosa B= tumour extended through mucosa to muscle layer C= involvement of lymph nodes D= distant metastatic disease
What is the treatment for colorectal cancer?
Surgery
Chemotherapy
Radiotherapy (rectal only)
What is the palliative treatment for colorectal cancer?
Chemotherapy
Colonic stenting
What test is used to screen the population for colorectal cancer?
FOB (faecal occult blood ) test
What are the high risk groups that must be screened?
Inflammatory bowel disease
Previous adenomas/CRC
Familial risk
Heritable conditions (familial adenomatous polyposis, hereditary non polyposis colorectal cancer)
What is familial adenomatous polyposis?
Autosomal dominant condition
Mutation of APC gene on chromosome 5
Caan get desmoid tumours or extracolic manifestations
What is hereditary non polyposis colorectal cancer?
Autosomal dominant condition
Mutation in DNA mismatch repair genes
