[Implication of radiological pattern in the prognosis of oligodendroglial tumors: correlation with genetic profile]

1p19q loss of heterozygosity (LOH1p19q) in oligodendroglial tumors has shown to be prognostic of prolonged survival and predictive of therapeutic responsiveness. During the last years, research is actively being directed to the discovery of radiological characteristics related to LOH1p19q. AIMS. To confirm the existence of molecular heterogeneity in oligodendroglial tumors in relation to their anatomic distribution, and to evaluate the correlation between molecular profile and other radiological and clinical characteristics and their prognostic impact.

Fifty-four patients with oligodendroglial tumors managed according to a previously established protocol were included. Preoperative SE T1, T1 post-gadolinium and T2 magnetic resonance images were reviewed by two independent neuroradiologists, blinded to clinical and molecular information. LOH analysis was assessed from paired tumor-blood DNA acid samples.

LOH1p was highly associated with LOH19q (p < 0.0001), LOH1p (odds ratio, OR = 6.19; 95% confidence interval, 95% CI = 1.66-22.68; p = 0.004), LOH19q (OR = 7.59; 95% CI = 1.84-31.34; p = 0.006) and LOH1p19q (OR = 5.38; 95% CI = 1.51-19.13; p = 0.007) were found to be more frequent in tumors located in the frontal lobe. Frontal location (hazard ratio, HR = 4.499; 95% CI = 1.027-193.708; p = 0.046), ring enhancement (HR = 0.213; 95% CI = 0.065-0.700; p = 0.011) and extent of resection (HR = 9.231; 95% CI = 1.737-49.050; p = 0.009) resulted independent prognostic factors for overall survival in the multivariate analysis.

Glioma classification aims to better define patients prognosis. Besides histological and immunohistochemical analyses, molecular information has become of great importance. Our results indicate that the evaluation of some MR features may also be useful. Efforts must be directed toward the use of every available resource at each institution.