Chromosomal anomalies in oligodendroglial tumors are correlated with clinical features.

Patients who have oligodendrogliomas (OD) that demonstrate loss of both 1p and 19q appear to have a better prognosis after they receive chemotherapy and radiotherapy compared with patients who have OD without these characteristics. It is unclear whether this improvement in outcome is due only to a better response to treatment. The authors investigated the correlation between genetic and clinical characteristics of OD in 33 patients who received chemotherapy with procarbazine, lomustine, and vincristine for recurrent disease after receiving radiotherapy. The initial presentation, prior treatments, overall survival, and response to chemotherapy were assessed. The 1p and 19q status in OD lesions was determined with fluorescence in situ hybridization on paraffin embedded, archival material using locus specific probes. P53 mutations were assessed by polymerase chain reaction-single-strand conformation polymorphism analysis and immunohistochemistry for P53; the proliferation index was assessed with the MIB-1 antibody. Patients who had OD lesions with a combined loss of 1p and 19q typically presented with low-grade tumors that manifested with seizures of long-standing duration. In contrast, patients who had OD lesions without a combined loss of 1p and 19q usually presented with focal deficits that required immediate treatment. Both the response rate to chemotherapy and the time to disease progression after chemotherapy were significantly better in patients who had a combined loss of 1p and 19. Tumors with classic OD morphology more often had a combined loss of 1p and 19q, although the genotype was better at identifying patients with chemoresponsive tumors. P53 mutations were observed in three tumors, none of which had a combined loss of 1p and 19q. OD lesions with combined a loss of 1p and 19q have a more indolent nature compared with OD lesions that do not have these losses. Virtually all patients with these tumors present with low-grade tumors accompanied by seizures and remain stable for prolonged periods. Future trials must keep these tumor types apart.

van den Bent MJ ，Looijenga LH ，Langenberg K ，Dinjens W ，Graveland W ，Uytdewilligen L ，Sillevis Smitt PA ，Jenkins RB ，Kros JM ... -  《CANCER》

Successful treatment of low-grade oligodendroglial tumors with a chemotherapy regimen of procarbazine, lomustine, and vincristine.

Anaplastic oligodendroglioma (OD) tumors, especially those with the combined loss of the short arm of chromosome 1 (1p) and the long arm of chromosome 19 (19q), are sensitive to chemotherapy. Only limited data are available on the role of chemotherapy in low-grade OD. The authors retrospectively studied the outcome of the procarbazine, lomustine, and vincristine (PCV) chemotherapy regimen in a group of 16 patients with newly diagnosed OD and 5 patients with recurrent low-grade OD. Two groups of patients were studied: newly diagnosed patients with large OD and mixed oligoastrocytomas (OA) and patients with recurrent OD and OA after radiotherapy who still showed nonenhancing tumors. Treatment consisted of standard PCV chemotherapy. In the newly diagnosed and responding patients, radiotherapy was withheld until the time of disease recurrence. Responses were assessed by T2-weighted magnetic resonance image (MRI) scans. Loss of chromosome 1p and 19q was assessed using fluorescent in situ hybridization with locus-specific probes. Three of five patients with recurrent tumors responded. Thirteen of the 16 newly diagnosed patients showed evidence of response. The median time to disease progression in this group was >24 months. Only one of these patients experienced disease progression while receiving chemotherapy. Several patients showed a signficant clinical improvement despite only a modest improvement of the tumor on the MRI scans. Even patients without loss of 1p or 19q showed satisfactory responses. No TP53 mutations were found. Newly diagnosed patients with OD tumors, with or without loss of 1p/19q, responded to PCV chemotherapy. Up-front chemotherapy may be indicated especially for patients with large tumors. MRI scans were of limited value for the assessment of response. A Phase III trial should be initiated to compare radiotherapy with chemotherapy.

Stege EM ，Kros JM ，de Bruin HG ，Enting RH ，van Heuvel I ，Looijenga LH ，van der Rijt CD ，Smitt PA ，van den Bent MJ ... -  《CANCER》

The prognostic impact of histology and 1p/19q status in anaplastic oligodendroglial tumors.

McDonald JM ，See SJ ，Tremont IW ，Colman H ，Gilbert MR ，Groves M ，Burger PC ，Louis DN ，Giannini C ，Fuller G ，Passe S ，Blair H ，Jenkins RB ，Yang H ，Ledoux A ，Aaron J ，Tipnis U ，Zhang W ，Hess K ，Aldape K ... -  《CANCER》

Clinical use of genotype to predict chemosensitivity in oligodendroglial tumors.

Walker C ，Haylock B ，Husband D ，Joyce KA ，Fildes D ，Jenkinson MD ，Smith T ，Broome J ，du Plessis DG ，Warnke PC ... -  《-》

Allelic losses at 1p36 and 19q13 in gliomas: correlation with histologic classification, definition of a 150-kb minimal deleted region on 1p36, and evaluation of CAMTA1 as a candidate tumor suppressor gene.

Barbashina V ，Salazar P ，Holland EC ，Rosenblum MK ，Ladanyi M ... -  《CLINICAL CANCER RESEARCH》