LWBK1006-28 LWW-Govindan-Review December 9, 2011 16:52
390 DeVita, Hellman, and Rosenberg’s CANCER: Principles and Practice of Oncology Review6 cm, astrocytoma histology, and incomplete resection were identified
as adverse prognostic factors, with the presence of three or more of these
factors conferring poor prognosis. In such patients, immediate postoper-
ative radiotherapy is recommended.Answer 28.13. The answer is D.
The prognosis for recurrent GBM is poor with a median survival of 3
to 9 months when using traditional chemotherapeutic agents. However,
several recent publications have demonstrated a significant improvement
in patients with recurrent GBM using the angiogenesis inhibitor beva-
cizumab.Answer 28.14. The answer is C.
For patients with GBM, standard radiation therapy is 60 Gy in 30 or
33 fractions. The Medical Research Council study reported a survival
advantage in patients receiving a 60 Gy dose versus a 45 Gy dose (12
vs. 9 months,p=.007). In an RTOG/ECOG study, patients receiv-
ing 60 Gy followed by a 10 Gy boost did not have a survival advan-
tage over patients receiving the standard 60 Gy dose. Hyperfractionated
and accelerated regimens have likewise not shown survival advantage. In
the phase I/II RTOG 8302 study, hyperfractionated doses with 64.8 Gy,
72 Gy, 76.8 Gy, and 81.6 Gy in 1.2 Gy twice daily fractions did not
show a survival benefit between the different treatment arms. This study
included treatment arms with accelerated hyperfractionated regimens of
48 Gy and 54.4 Gy in 1.6 Gy twice daily fractions, which also did not lead
to survival benefit. Adjuvant temozolomide with radiation was shown to
improve overall survival compared with radiation alone in a randomized,
phase III trial for patients with GBM (14.6 vs. 12.1 months).Answer 28.15. The answer is A.
Surgical resection is the primary treatment of patients with ependymoma.
There are no definitive recommendations for the addition of radiotherapy
to the treatment. However, tumors in the posterior fossa cannot always
be fully resected, and patients undergoing resection alone have a very
high incidence of local recurrence. Therefore, adjuvant focal radiother-
apy to the site of the tumor may be added in the treatment of patients
with ependymoma. In one study, patients receiving focal radiotherapy of
more than 45 Gy to the tumor bed had 5- and 10-year survival rates of
67% and 57%, respectively. The addition of focal radiotherapy has been
shown to improve 10-year survival from 67% in patients treated with
gross total resection (GTR) alone to 83% in patients treated with GTR
and radiotherapy. MGMT gene methylation is associated with better sur-
vival in patients with GBM. In ependymomas, there has been no reported
association between MGMT gene methylation and survival. There is no
evidence to date supporting the use of chemotherapy for treating ependy-
moma.