GIST FRCR CO2A

Question 1

MC site for GIST

Answer 1

stomach
small intestine

Question 2

origin of GIST

Answer 2

interstitial cells of Cajal (responsible for gut motility)

Question 3

RFs for GIST

Answer 3

1. Sporadic
2. familial GIST , inherited mutation in KIT

Question 4

Syndromes a/w GIST

Answer 4

1. Carney Triad
2. Carney Stratakis Syndrome
3. Type I NF
4. Von Reclinghausen

Question 5

carney Triad

Answer 5

young females

Triad of
1. gastric GIST
2. Paraganglioma
3. Pulmonary Chondroma

Question 6

mutations in GIST

Answer 6

KIT (CD 117) 75 to 80%

s/times KIT - PDGFRA +

s/times no detectable mutations (syndromes)

Question 7

histological feature of GIST

Answer 7

submucosal
grow endophytically
well circumscribed, whorled, fibroid like

larger lesions: cystic degeneration

Question 8

CD117 + tumors

Answer 8

Melanoma
Angiosarcoma
Seminoma

Question 9

who should not be Rx with Imatinib

Answer 9

PDGFRA mutated GIST

Question 10

How does GIST spread?

Answer 10

local spread

rarely through LNs

mets: Liver, lung peritoneum bone etc

Question 11

presentation of GIST

Answer 11

emergency with intestinal H’ge or obstruction

Bleeding (50%)
Pain (25 %)
GI obstruction ( 10 to 30 %)

Asymptomatic in 25 to 30%

Question 12

Investigations for staging

Answer 12

CT Thorax Abdomen and pelvis

Question 13

is percutaneous Bx advised for GIST?

Answer 13

No, risk of necrotic tumor leakage from the biopsy site

Question 14

Staging for GIST

Answer 14

localized and metastatic

LN +: metastatic

Question 15

Risk Stratificaiton for GIST

Answer 15

Tumor Size and Mitotic Rate

Question 16

when is adjuvant therapy with Imatinib started

Answer 16

High risk of recc, as per stratification

Question 17

SOC for inoperable or if residual/metastatic disease GIST

Answer 17

Imatinib

Question 18

WHat’s the primary aim of Sx in GIST?

Answer 18

complete resection while avoiding tumor rupture

Question 19

Margin for Tumor > 2cm

Answer 19

WLE with margin of 1 to 2 cm

Question 20

Lymphadenectomy in GIST?

Answer 20

Not required

Question 21

Small tumors <2 cm

Answer 21

controversial management

Resection, if not, re imaged at 6 and 12 months with a CT or EUS

Question 22

Duration of Imatinib in adjuvant setting?

Answer 22

3 yrs (scandinavian German Study)

Question 23

Indications of Imatinib in GIST

Answer 23

CD 117 (KIT) +
inoperable recurrent or metastatic

Question 24

Baseline Investigations b4 Imatinib

Answer 24

FBC
LFT
RFT

avoid pregnancy and breast feeding

look for drug interaction via p450 system

Question 25

how to take imatinib

Answer 25

400 mg PO OD Continuously taken with a large glass of water (to avoid gastric irritation) Avoid Caffeine and grapefruit for 1 hr b4 and after receiving the dose avoid lying down for 1 hr afterward

Question 26

Monitoring of pt on imatinib

Answer 26

2 wks post starting LFT/CBC, assess toxicity and weight repeat at 4 to 6 weeks

Question 27

when is response assessment done after starting imatinib

Answer 27

@ 3 months with PET CT

Question 28

Why should weight of pt on imatinib be monitored

Answer 28

to assess fluid retention

Question 29

S/Es of Imatinib

Answer 29

1. Nausea and Vomiting 2. Fluid Retention 3. Diarrhoea and dyspepsia

Question 30

How is fluid retention treated?

Answer 30

Diuretic therapy if severe, stop imatinib

Question 31

when altered LFT requires imatinib termination?

Answer 31

Bil > 3 x ULN ALT/AST > 5 x ULN

Question 32

should gi bleeding stop imatinib

Answer 32

it occurs often due to response and tumor regression

Question 33

2nd L post imatinib

Answer 33

Sunitinib

Question 34

reason for resistance to imatinib

Answer 34

secondary mutations

Question 35

Dose of sunitinib

Answer 35

50 mg D1 to D 28, gap of 2 weeks

Question 36

Dose reduction of sunitinib

Answer 36

if intolerant, 37.5 mg every day

Question 37

TOXICITIES OF SUNITINIB

Answer 37

1. fatigue, diarrhoea, nausea and skin discoloration 2. Thyroid dysfunction, HTN, mucositis, PPE, hepatic and cardiac toxicities including cardiomyopathy and arrhytmias

Question 38

monitoring of pts on sunitinib

Answer 38

Regular blood tests Regular BP Thyroid Function

Question 39

other Rx options in GIST, advanced

Answer 39

dose escalation of imatinib upto 800 mg daily

Question 40

imaging for response assessment

Answer 40

CT Scan

Question 41

R1 resection

Answer 41

re-resection if not possible, adjuvant imatinib

Question 42

NA imatinib?

Answer 42

not standard may have a role in borderline resectable cases

Question 43

F/U imaging frequency

Answer 43

1. all pts should have a CT scan at 3 months post Surgery Very Low Risk : no further CT, annual review Low Risk: CT @ 12 months, thereafter if clinically indicated Intermediate RISK: CT @ 9 months and then annual for 5 yrs High RISK: Adjuvant therapy and CT every 6 months for 3 yrs then annual for 5 yrs, Clinical review every 6 months