Ewings Sarcoma Flashcards
Ewings Sarcoma originates from
Neuroectoderm
Most commonly seen in
Lower extremities > Upper extremities
Axial skeleton 25%
Pelvis 25%
Femur 20%
Pathology Patho gnomic findings
Small round blue cell tumor
what are all the small round blue cell tumors
LEARN & RM (~ learn and remember)
L: Lymphoma
E: Ewings sarcoma
A: ALL
R: Rhabdomyosarcoma
N: Neuroblastoma/Neuroepithelioma
R: Retinoblastoma
M: Medulloblastoma
Median Age, sex and race
10-15 yrs
Caucasians
Males
Ewings family tumors
Ewings sarcoma - 87%
Ewings extraosseous sarcoma - 8%
Peripheral PNET - 5%
Askins tumor - PNET of chest wall: Sarcoma fo the ribs -> pleural extension
Staging
NO formal staging
75% localised
25% have Mets
Common sites of mets
Lungs
H & P
Don’t forget to do Neuro and MSK examination
Labs
CBC, CMP, LDH, ESR, UA
Imaging
X-ray: Lytic, sclerotic, moth eaten, onion skin, codman triangle
MRI with contrast: needed for diagnosis
CT Chest
PET-CT
X-Ray findings
Onion skin appearance = Periosteal stranding.
Periosteum is displaced by underlying tumor.
Seen in the Diaphysis of the bone
DD for periosteal stranding/thickening
Ewings Sarcoma
Osteosarcoma
Fractures
Osgood-Schlatter disease
Diagnostic study, Pathology form where
Bone marrow biopsy - Bilateral and from the tumor
CT guided core needle biopsy
Common translocations
EWSR 1 gene translocation
t(11:22) - 85%
t(21:22) - 5-10%
(q24:q12)
(q21:Q12)
Treatment paradigm
Induction Chemotherapy x 6 cycles followed by
Local therapy @ week 12 either with SX or XRT followed by
Chemotherapy x 11 cycles (upto 48 weeks total) followed by
Consolidation of met sites if any
Chemotherapy
Dose Dense VDC q 2 weeks
V: Vincristine
D: Adriamycin
C: Cyclophosphamide
Response rate to induction chemotherapy
90%
Adults chemo
q 3 weeks as they do not tolerate well
SX
Preferred over XRT in children due to risk of secondary malignancy from XRT
Better local control
XRT
Pre -Op if you think there will be close margins
Adjuvant XRT given along with chemotherapy week 14.
3600- Pre-OP
4500 - Definitive RT
5040- PORT
Volumes
GTV 1: Pre chemo T2flare with modified margins
CTV 1: GTV1 + 1cms = 4500cGy/25fx (for extra osseous & LN can go upto 5040 and no need GTV2)
GTV 2: Post tissue soft tissue tumor + Pre chemo bone volume
CTV 2: GTV2 + 1cms = 5580cGy/33fx
Metastatic disease consolidation
Given after all the chemotherapy
SBRT: 40Gy/5fx to gross disease and 35Gy to 3mm expansion
Lung Mets: Whole lung irradiation 15Gy/10fx with boost to gross disease with 45Gy
Ascites: Whole abdomen radiation: 24Gy/16fx
PORT
50% risk of local failure.
PORT is given when
- Close margin <1cm for bone. <0.5cm for soft tissue
- Intraoperative tumor spill
- <90-95% necrosis
5-yr OS for extremity localized disease
80%
5-yr OS for Pelvic localized disease
60%
5-yr OS for Lung mets
50%
5-yr OS for bone marrow mets
30%
Local failures occur in the first
2 years
Staining
PAS
MIC2 glycoprotein
Vimentin
Negative for
S100
NSE
Clinical Symptoms
Pain >90%
Swelling/mass
Limitation of motion
pathological fractures
fever
Poor Prognostic factors
MASS LDH
M: Male
A: Age>17
S: Site, Size>8cm
S: Stage
LDH: High
P53 expression
INK4A deletion
What markers help differentiate between EWS and other small round cell tumors
Increase in MYC
B2 microglobulin
HBA-71
Vimentin
What markers help differentiate between EWS and PNET
PNET = S-100 and NSE +ve
EWS = Homer Wright rosettes
What showed to improve the 5 year event free survival
reducing the time between chemo cycles form 21 days to 14 days
