Chemosensitivity of Oligodendroglial Tumors: Genetic Factors

Absalyamova .*, Korshunov .*, Lichinzer .**, Loshakov V.*, Kobyakov G.*, Pronin I.*, Golanov .*

* Burdenko Research Institute of Neurosurgery, Moscow, Russia;
** Russian Oncological Scientific Centre, Moscow, Russia


Introduction. Oligodendroglial tumors, represented by oligodendrogliomas (O) and anaplastic oligodendrogliomas (AO), as well as such mixed neoplasms as oligoastrocytoma (OA) and anaplastic oligoastrocytomas (AOA) are characterized by more favorable prognosis and higher sensitivity to radio- and chemotherapy in comparison with astrocytic tumors. However, there is no absolute correlation between a degree of anaplasia and prognosis, typical of these tumors.

Material and Methods. There were 137 cases (82 males and 55 females), treated in the Burdenko Research Institute of Neurosurgery in 1999-2005. Their mean age was 39.5 years (16-64). Histological versions of tumors were as follows: O - 24, AO - 54, OA - 29, AOA - 30. Chemotherapy was used both an adjuvant (98 cases after tumor removal) and main (39 cases after stereotaxic biopsy) method of treatment. Based on nitrosurea derivatives, it was carried out in the PCV (lomustine, vincristine, natulan) and PNV (nidran, vincristine, natulan) modes or as monotherapy with mustophoran. The results were compared with data on 189 cases with oligodendroglial or mixed tumors, who were not subject to adjuvant chemotherapy. Tumor genome was analyzed with applying in situ fluorescent hybridization with molecular probes, a quantitative polymerase chain reaction and matrix comparative genomic hybridization for revealing codeletion of 1p19q, deletions of 9p and 10q, EGFR gene amplification and some other chromosomal aberrations.

Results. There was correlation between codeletion of 1p19q and tumor chemosensitivity. Our further step is developing a differentiated approach to treatment with taking into account molecular-genetic factors.