Co-polysomy of 1p/19q in glial tumors: Retrospective analysis of 221 cases from single center.

Glial tumors are malignant brain tumors that arise from glial cells of brain or spine and have genetic aberrations in their genome. 1p/19q co-deletion is associated with increased Overall Survival (OS) time with enhanced response to chemo- and radio-therapy in oligodendrogliomas. However, prognostic significance of 1p/19q co-polysomy is still unclear. We evaluated 1p/19q status of 221 patients with glial tumor by Fluorescent in situ Hybridization (FISH). Records of the patients were collected retrospectively. Our results demonstrated that 1p/19q co-polysomy was associated with decreased OS time, high P53 expression and frequently located in temporal lobe, whereas 1p/19q co-deletion was associated with increased overall survival time, low P53 expression and frontal lobe location. Furthermore, classification of patients based on both 1p/19q status and P53 expression revealed that patients with 1p/19q co-polysomy and high P53 expression had the worst prognosis. Lastly, our bioinformatic survival analysis revealed that high expression of SRM, ICMT, and FTL located in 1p36.13-p36.31 and 19q13.2-q13.33 region were related with decreased OS time in patients with Low Grade Glioma (LGG). The study demonstrated that 1p/19q co-polysomy is a poor prognostic marker for glial tumor.