BPT Gastroenterology Flashcards
FAP - genetic abnormality and inheritance
Germline mutation of tumour suppressor gene APC on 5q21-22, autosomal dominant
Endoscopic surveillance in FAP
Flexi-sig every 1-2 years from 12-15 until polyposis develops, then prophylactic colectomy.
If genetic test negative, sigmoidoscopy Q3 years if no polyposis; normal population screening after 55y.
Gastroscopy at polyposis onset or after 25y.
MUTYH associated polyposis
Autosomal recessive biallelic mutation in MUTYH; similar presentation to FAP. Also risk of ovarian, bladder, skin, breast cancer; gastroduodenal polyps. 2-yearly colonoscopy, gastroscopy 2-5 yearly from 25-30y.
Serrated polyposis syndrome criteria
> 1 of
5 serrated polyps proximal to sigmoid with 2 x >10mm
any number of serrated polyps proximal to sigmoid in 1st degree relative of someone with SPS
20 serrated polyps of any size throughout colon
Serrated polyposis syndrome mutation
Hypermethylation of numerous genes and activating BRAF mutations; also associated with MUTYH and MBD4 mutations
HNPCC Amsterstam II criteria
3-2-1 rule
- 3 relatives with Lynch-associated cancers, one should be a first degree relative of other two; FAP excluded
- 2 successive generations affected
- 1 cancer diagnosed before 50
HNPCC Bethesda criteria
Criteria for individuals with CRC to be tested for MSI, needs 1+ of
* CRC diagnosed 1 first degree relative with HNPCC-related tumours (1 diagnosed 1st degree relative
HNPCC screening guidelines
Colonoscopy: Q2y from 25y or 5y earlier than youngest diagnosis, alternating with FOBT between scopes.
Gastroscopy: Q2y from 30y
Uterine / ovarian: TVUS yearly from 30y or 3-5y earlier than youngest diagnosis
Urinalysis yearly from 30y
Vedoluzimab - mechanism of action, side effects
Alpha-4-beta-7 integrin inhibitor.
Impedes lymphocyte trafficking in GI and CNS. Risks: infusion reactions, infections, optic neuritis, lupus like reactions. No PML association seen as yet.
Used in IBD.
