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growth, whatever their histological subtypes. The radiological tumor growth is eas-
ily quantifi ed by measuring the evolution of the equivalent tumor diameter (calcu-
lated from the tumor volume), obtaining the Velocity of Diametric Expansion
(VDE). The spontaneous VDE of LGG varies markedly with an average VDE of
about 4 mm/year. It depends on intrinsic factors (1p19q codeletion status, P53 over-
expression status) and can be modifi ed by extrinsic factors such as pregnancy. VDE
has a strong prognostic signifi cance regarding progression free and overall surviv-
als. Therefore, VDE should be integrated along with the other “static” parameters
(multimodal imaging, histological and molecular analyses) in the initial investiga-
tions (Pallud et al. 2012 ). Assessment of VDE obtained before, during, and after
cancer therapy helps in analyzing the effects on an individual basis as a guide to the
decision in management.
Personalized Therapy of Oligodendroglial Tumors (OTs)
Oligodendroglial tumors (OTs) constitute one-third of gliomas and their distinction
from astrocytic gliomas is important both for prognosis and therapy, but is often not
adequately accurate. Because response to chemotherapy varies and the adverse
effects may outweigh benefi ts in pathological types of tumors that do not respond to
chemotherapy, there is thus an urgent need for refi ned diagnostic markers to improve
glioma classifi cation and predicting their chemosensitivity. LOH markers or in situ
hybridization probes mapping to 1p36 have been used to identify chemosensitive
OTs. It has become increasingly clear, however, that not all chemotherapy-sensitive
OTs can be identifi ed by this limited set of diagnostic tools, and that some OTs,
despite their loss of 1p, are chemoresistant. Novel predictive diagnostic tools are
being developed for personalizing the treatment of OTs by aiming to: (i) defi ne a
molecular profi le capable of identifying all gliomas that are sensitive to procarba-
zine, lomustine, and vincristine (PCV): and (ii) to identify genes/signaling path-
ways involved in PCV chemosensitivity.
Anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA) are
treated with surgery and radiotherapy (RT) at diagnosis, but they also respond PCV,
raising the possibility that early chemotherapy will improve survival. A randomized
clinical trial showed that for patients with AO and AOA, PCV plus RT does not
prolong survival. Longer progression-free survival after PCV plus RT is associated
with signifi cant toxicity. A signifi cant fi nding of this trial was that tumors lacking
1p and 19q alleles are less aggressive or more responsive or both (Cairncross et al.
2006 ). The specifi c chromosomal change in oligodendroglial brain tumors is thus
associated with a very good prognosis and may also identify patients who would
benefi t from chemotherapy treatment in addition to radiotherapy at diagnosis for
long-term tumor control. The fi ndings could change the future of how brain cancers
are diagnosed and treatments are personalized based on genetic make-up of the
tumor. Testing for chromosomal deletions should be a mandatory part now of the
management of patients with these tumors.
10 Personalized Therapy of Cancer