Cancer - Clinical

Question 1

CRC location prevalence

Answer 1

¼ rectal; 1/3 right sided (inc transverse colon, splenic flexure is junction)

left is rest

Question 2

Genetic cause leading to most MSI CRCs?

Answer 2

BRAF mutation
i.e. sporadic not Lynch syndrome/ inherited

Question 3

3 main subtypes of CRC molecularly?

Answer 3

• CIN (APC pathway, classical)
• MSI-H (Lynch/HNPCC or BRAF)
• CIMP

Question 4

CRCs related to CIMP pathway?

Pathophys (basic)

Answer 4

“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

Question 5

Most common mutations that cause Lynch syndrome

Answer 5

MLH1 + MSH2 account for > 90%

Question 6

most common presentation of CRC in Lynch syndrome by age and sidednessn(< or > 50, L or R)

Answer 6

< 50,
R

Question 7

Mutation suggestive that CRC with MSI is sporadic rather than germline MSI mutated?

Answer 7

BRAF mutation

Question 8

Genetic change in MUTYH-associated polyposis

Answer 8

neo APC mutation

heterogenous MUTYH mutation - AR

phenotypically like FAP

Question 9

Common cancer with FAP (other than CRC)

Answer 9

papillary thyroid, ileal carcinoid, gastric cancer

Question 10

t stages in CRC

Answer 10

T1 into mucosa
T2 into muscularis propria
T3 through muscularis propria

Question 11

Number LNs to sample in CRC operation

Answer 11

at least 12 (< this and inadequate sampling, might stage wrong)

Question 12

Endocarditis from which bacteria associated with CRC?

Answer 12

Streptococcus gallolyticus

(Previously known as strep bovis )

Question 13

5FU/ capecitabine main AE

Answer 13

diarrhoea,
HFS (hand foot syndrome),
coronary vasospasm

Question 14

Oxaliplatin main AE

Answer 14

cold-induced neuropathy
- not permanent
- cold air/ sensation very uncomfortable

peripheral neuropathy
- can get worse even after it’s stopped

Question 15

Irinotecan main AE

Answer 15

diarrhoea,
entero-hepatic recirculation of the active metabolite SN38

Question 16

Target of cetuximab

Answer 16

EGFR transmembrane protein

Question 17

EGFR pathway in CRCx

Answer 17

Question 18

Mutation requirements for cetuximab to be effective in CRC?

Answer 18

Need to be RAS/ RAF wild type

Question 19

AE of cetuximab

Answer 19

rash (correlates with activity) - acneiform
diarrhoea,
renal salt wasting;
worse toxicity in combination with capecitabine

Question 20

Class and AE of bevacizumab

Answer 20

VEGFi

hypertension,
proteinuria,
GI perforation,
thromboembolic events,
delayed wound healing

Question 21

Mechanism of Bevacizumab

Answer 21

MoAb against VEGF-A ligand

Question 22

Radiation benefit in hepatic cancer/ mets

Answer 22

very low,

Very rare to irradiate liver. Low tolerance to radiation generally

Question 23

Buzzwords for GIST

Answer 23

spindle shaped cells
CD117/ C-kit positive

Question 24

Drug for GIST

Answer 24

imatinib (400mg)
(can actually increase the dose if it gets worse -> 800mg or more)