Correlations between molecular profile and radiologic pattern in oligodendroglial tumors

Objective: To investigate possible correlations between tumor location and genetic alterations in a series of oligodendrogliomas. Methods: A series of 158 consecutive oligodendrogliomas were retrospectively reviewed. In each case, the radiologic picture and the chromosome 1p (chr 1p) status of the tumor detected by the loss of heterozygosity technique were analyzed. Correlation between tumor location and molecular profile was made by χ2 tests. Results: Eighty-eight of the 158 patients had low-grade oligodendrogliomas, and 70 had anaplastic oligodendrogliomas. Overall, oligodendrogliomas with chr 1p loss were located preferentially in the anterior part of the brain, whereas tumors with intact chr 1p affected mainly the posterior part of the brain (p = 0.0038). In terms of lobar involvement, a preferential location of oligodendrogliomas with chr 1p loss was found in the frontal lobes as compared with the temporal, parietal, and occipital tumors (p < 0.01). Conclusion: There is a significant correlation between loss of heterozygosity on chromosome 1p and tumor location in oligodendrogliomas, suggesting that subtypes of oligodendrogliomas could derive from site-specific precursors.