Colorectal polyps and cancer Flashcards
What are colorectal polyps?
Small growths on lining of colon or rectum
Very common and not usually serious but can progress to cancers
Which 2 conditions massively increase risk of polyps?
Familial adenomatous polyposis (FAP)
and
Hereditary Non Polyposis Colon Cancer (HNPCC or Lynch syndrome)
What is the mutation in familial adenomatous polyposis?
Autosomal dominant APC gene mutation
APC gene = Adenomatous polyposis coli, tumour supressor
What does Familial adenomatous polyposis (FAP) cause?
1000s of polyps which will inevitably cause colorectal cancer
How is Familial Adenomatous polyposis (FAP) often managed?
Complete removal of colon (total colectomy) or colon and rectum (proctocolectomy)
What is the mutation in Hereditary Non Polyposis Colon Cancer?
Autosomal dominant MSH 1 mutation
MSH 1 = DNA mismatch repair gene
What does HNPCC mean?
Impaired DNA mismatch repair gene meaning much greater risk for colon cancer and increases progression of adenoma to adenocarcinoma
What are risk factors for colorectal cancer?
Polyps/adenomas
Familial inherited genetic predisposition (like FAP or HNPCC)
Alchol
Smoking
Ulcerative colitis
What do colorectal cancers commonly metastasise to?
Liver
Lung
What are symptoms of colorectal cancer?
Pain in distal colon (sigmoid onwards)
Pain in LLQ
Bloody mucousy stools (fresh blood means closer to anus)
Tenesmus
What is tenesmus?
The feeling you need to pass stool despite bowels being empty. may involve straining, pain and cramping
How do you diagnose colorectal cancer?
FIT test (faecal occult):
screens for microblood in poo
2 week wait referral for colonoscopy/biopsy
Gold standard = colonoscopy and biopsy
How is colorectal cancer classified?
TNM
When are FIT screening tests done?
All people over 60 with iron deficiency anaemia and change in bowel habit
What is treatment for colorectal cancer?
Surgery if no mets
Chemo
