1537 / 1708
St Jude RT1 cohort received adjuvant postoperative radiation.
Strikingly, survival for STR EPN_PFA was not different between
those who received
fi
rst-line external-beam radiation and those
who did not in the CERN and Burdenko cohorts (Appendix
Fig A6,
online only). In the GENE cohort, there was a statistically sig-
ni
fi
cant difference by a univariable analysis in patients who did not
receive radiation; however, survival remains poor even in patients
with subtotal resections who received external-beam irradiation.
These data suggest that the bene
fi
t of post-surgical
fi
rst-line
adjuvant external-beam irradiation for patients with EPN_PFA
is limited in the face of a subtotal resection and that these patients
should be prioritized for clinical trials of novel therapy.
Patients With GTR EPN_PFB Have an Excellent
Prognosis
As a result of limited patient numbers, we combined patients
with EPN_PFB from the GENE, St Jude RT1, and CERN cohorts
and demonstrated that STR results in a high risk of relapse (10-year
PFS for GTR, 0.740; 95% CI, 0.550 to 0.859; 10-year PFS for STR,
0.50; 95% CI, 0.271 to 0.692). These
fi
ndings were con
fi
rmed in
a cohort of patients with EPN_PFB treated at the Burdenko In-
stitute
( Fig 3 ). As a result of the similar behavior of the two cohorts
and the relatively small number of patients with EPN_PFB in each
cohort, we combined all patients in our subsequent multivariable
analysis. In a multivariable analysis restricted to EPN_PFB, a similar
P
= .4
0.25
0.50
0.75
1.00
0 1 2 3 4 5 6 7 8 9 10
Time Since Diagnosis (years)
OS (probability)
No first-line XRT
First-line XRT
29 27 26 25 21 19 18 14 11 8 5
61 56 52 46 38 36 30 25 21 16 14
No first-line XRT
First-line XRT
No. at risk
P
= .1
0.25
0.50
0.75
1.00
0 1 2 3 4 5 6 7 8 9 10
Time Since Diagnosis (years)
PFS (probability)
29 26 25 24 20 18 17 14 11 8 5
61 55 49 44 36 35 29 24 20 14 13
No first-line XRT
No first-line XRT
First-line XRT
No. at risk
B
A
P
= .6
0.25
0.50
0.75
1.00
0 1 2 3 4 5 6 7 8 9 10
Time Since Diagnosis (years)
PFS (probability)
No first-line XRT
First-line XRT
7 6 6 6 5 4 4 3 2 1 1
40 36 29 21 17 13 9 6 5 4 2
First-line XRT
No first-line XRT
First-line XRT
No. at risk
P
= .3
0.25
0.50
0.75
1.00
0
1 2 3 4 5 6 7 8 9 10
Time Since Diagnosis (years)
OS (probability)
7 7 6 6 5 4 4 4 2 1 1
39 37 34 27 23 18 13 9 8 5 2
No. at risk
D
C
No first-line XRT
First-line XRT
No first-line XRT
First-line XRT
Fig 3.
Value of adjuvant post-operative
fi
rst-line external-beam irradiation (XRT) in EPN_PFB. (A) Progression-free survival (PFS) and (B) overall survival (OS) of EPN_PFB
across the Global Ependymoma Network of Excellence, St Jude
’
s, and Collaborative Ependymoma Research Network cohorts. (C) PFS and (D) OS of EPN_PFB across the
Burdenko cohort.
P
values determined using log-rank test.
6
© 2016 by American Society of Clinical Oncology
J
OURNAL OF
C
LINICAL
O
NCOLOGY
Ramaswamy et al
from 139.18.224.1
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Copyright © 2016 American S ciety of Clinical Oncology. All rights reserved.