Cancer - Clinical Flashcards
CRC location prevalence
¼ rectal; 1/3 right sided (inc transverse colon, splenic flexure is junction)
left is rest
Genetic cause leading to most MSI CRCs?
BRAF mutation
i.e. sporadic not Lynch syndrome/ inherited
3 main subtypes of CRC molecularly?
- CIN (APC pathway, classical)
- MSI-H (Lynch/HNPCC or BRAF)
- CIMP
CRCs related to CIMP pathway?
Pathophys (basic)
“serrated adenoma”
Right sided, older patients
C-G rich areas methylated, frequently found in promoter regions
* results in “epigenetic silencing”, which is multiple inactivated genes due to hypermethylation
Most common mutations that cause Lynch syndrome
MLH1 + MSH2 account for > 90%
most common presentation of CRC in Lynch syndrome by age and sidednessn(< or > 50, L or R)
< 50,
R
Mutation suggestive that CRC with MSI is sporadic rather than germline MSI mutated?
BRAF mutation
Genetic change in MUTYH-associated polyposis
neo APC mutation
heterogenous MUTYH mutation - AR
phenotypically like FAP
Common cancer with FAP (other than CRC)
papillary thyroid, ileal carcinoid, gastric cancer
t stages in CRC
T1 into mucosa
T2 into muscularis propria
T3 through muscularis propria
Number LNs to sample in CRC operation
at least 12 (< this and inadequate sampling, might stage wrong)
Endocarditis from which bacteria associated with CRC?
Streptococcus gallolyticus
(Previously known as strep bovis )
5FU/ capecitabine main AE
diarrhoea,
HFS (hand foot syndrome),
coronary vasospasm
Oxaliplatin main AE
cold-induced neuropathy
- not permanent
- cold air/ sensation very uncomfortable
peripheral neuropathy
- can get worse even after it’s stopped
Irinotecan main AE
diarrhoea,
entero-hepatic recirculation of the active metabolite SN38
Target of cetuximab
EGFR transmembrane protein
EGFR pathway in CRCx
Mutation requirements for cetuximab to be effective in CRC?
Need to be RAS/ RAF wild type
AE of cetuximab
rash (correlates with activity) - acneiform
diarrhoea,
renal salt wasting;
worse toxicity in combination with capecitabine
Class and AE of bevacizumab
VEGFi
hypertension,
proteinuria,
GI perforation,
thromboembolic events,
delayed wound healing
Mechanism of Bevacizumab
MoAb against VEGF-A ligand
Radiation benefit in hepatic cancer/ mets
very low,
Very rare to irradiate liver. Low tolerance to radiation generally
Buzzwords for GIST
spindle shaped cells
CD117/ C-kit positive
Drug for GIST
imatinib (400mg)
(can actually increase the dose if it gets worse -> 800mg or more)
