Correlations between molecular profile and tumor location in Chinese patients with oligodendroglial tumors

Objective To investigate possible correlations between molecular alterations and tumor location in Chinese patients with oligodendroglial tumors. Methods A series of 105 gliomas, including 42 oligoastrocytomas, and two control groups of 28 oligodendrogliomas and 35 astrocytomas, were retrospectively reviewed. In each case, the radiologic picture and loss of heterozygosity (LOH) on chromosome 1p and 19q detected by denaturing high-performance liquid chromatography (DHPLC) were analyzed. Correlations between molecular profile and tumor location were made by chi-square and Fisher’s exact tests. Results Oligodendroglial tumors located in the nontemporal lobes were significantly more likely to have combination of LOH 1p and LOH 19q than tumors arising in the insula, temporal lobe, and temporal with another lobe (p = 0.001). Subgroup analysis confirmed this finding in oligodendrogliomas (p = 0.006), but the difference did not reach significance in the oligoastrocytoma group, although the trend was similar (p = 0.067). In contrast to the oligodendroglial tumors, we detected no association between molecular alterations and location for diffuse astrocytomas. Conclusion We conclude that molecular subsets of oligodendroglial tumors may arise preferentially in certain lobes of the brain, with tumors having LOH 1p and LOH 19q occurring most frequently in the nontemporal lobes. These findings suggest that molecular subsets of oligodendroglial tumors may arise from site-specific precursor cells, which has provided some information for the current management of these neoplasms in China.