LWBK1006-28 LWW-Govindan-Review December 9, 2011 16:52
Chapter 28•Neoplasms of the Central Nervous System 389Answer 28.7. The answer is B.
Chromosome 22q loss is common in ependymomas; in spinal ependymo-
mas, this loss is associated with mutations of the NF2 gene. In cerebral
ependymomas, loss of chromosome 22q is not associated with NF2 muta-
tions.Answer 28.8. The answer is D.
In a randomized phase III trial, patients with GBM who were posi-
tive for MGMT gene methylation and treated with combined temo-
zolomide and radiation had significantly improved survival when com-
pared with patients who were either negative for MGMT gene methy-
lation or received radiation only. In another study, patients with GBM
had improved survival when treated with EGFR-TK inhibitors when
the tumors expressed the common form of mutated EGFR (activated
EGFRvIII) and retained PTEN function compared with patients not
expressing both of these biomarkers.Answer 28.9. The answer is A.
Primary CNS neoplasms are not usually associated with viral infections
in humans, except for primary CNS lymphoma, which is strongly associ-
ated with EBV. The majority of primary CNS lymphomas are large B-cell
histology, and EBV DNA is detectable in most of these tumors. In addi-
tion, the incidence of primary CNS lymphoma is higher in patients with
HIV infection.Answer 28.10. The answer is A.
Contrast-enhanced MRI images help differentiate between different types
of CNS tumors. MRI also helps to differentiate between high- and low-
grade tumors. Low-grade CNS tumors generally do not enhance, except
for pilocytic astrocytoma and pleomorphic xanthoastrocytoma.Answer 28.11. The answer is D.
Multivariate analysis from two large European phase III trials have
reported age greater than or equal to 40 years, tumor diameter greater
than or equal to 6 cm, tumor crossing the midline, astrocytoma histology,
and neurologic deficits to be associated with adverse prognosis.Answer 28.12. The answer is C.
Radiotherapy is not routinely recommended in patients undergoing resec-
tion for low-grade gliomas. In the European Organization for Research
and Treatment of Cancer (EORTC) 22845 trial, patients receiving imme-
diate postoperative radiotherapy had a progression-free survival advan-
tage compared with those receiving radiation therapy on tumor progres-
sion (5.3 vs. 3.4 years,p<.0001). There was no significant difference in
overall survival (7.4 years vs. 7.2 years). In another study, age greater
than or equal to 40 years, tumor diameter greater than or equal to