Turkish Neurosurgery
THE CORRELATION BETWEEN 1p/19q CODELETION, IDH1 MUTATION, p53 OVEREXPRESSION AND THEIR PROGNOSTIC ROLES IN 41 TURKISH ANAPLASTIC OLIGODENDROGLIOMA PATIENTS
Payam Hacısalihoğlu1, Zafer Kucukodaci2, Gokcen Gundogdu3, Bilge Bilgic3
1Yeni Yuzyil University Medical Faculty, Pathology, Istanbul,
2Gulhane Military Medical Academy, Pathology, Istanbul,
3Istanbul University Istanbul Medical Faculty, Pathology, Istanbul,
DOI: 10.5137/1019-5149.JTN.16832-15.1

Aim:The aim of our study is to observe the correlation between 1p/19q codeletion, IDH1 mutation and p53 protein overexpression and their prognostic value in Turkish anaplastic oligodendroglioma patients who were treated with adjuvant radiotherapy and temozolomide chemotherapy.Material and Methods:In our study we retrospectively evaluated 41 patients who were diagnosed as anaplastic oligodendroglioma. Thirty five patients received standard radiotherapy. Twenty six patients received standard temozolomide chemoterapy concurrent to radiotherapy. Results:We observed chromosome 1p/19q codeletion in 19 of 41 patients (46%) via Fluorescent In Situ Hybridisation (FISH) technique. Twenty six patients (63%) showed positive immunoreaction with anti-IDH1 antibody. Six patients (15%) showed positive immunoreaction with anti-p53 antibody. We determined a statistically significant correlation between chromosome 1p/19q codeletion and IDH1 mutation (p<0.0001). The patients who had tumors with chromosome 1p/19q codeletion and p53 overexpression were mutually exclusive. The mean estimated Progression Free Survival (PFS) of the patients who had tumors with chromosome 1p/19q codeletion and/or IDH1 mutation was determined to be significantly longer than that of the patients without these genetic changes, regardless of the treatment modality (p=0.006, p=0.004). PFS of the patients who received adjuvant chemotherapy and whose tumors had chromosome 1p/19q codeletion or IDH1 mutation was significantly longer than that of the patients without these genetic changes (p=0.001, p<0.0001).Conclusion:As a result of our study, chromosome 1p/19q codeletion and /or IDH1 mutation are determined to be statistically significant favorable prognostic factors in anaplastic oligodendroglioma patients, in terms of PFS.

Corresponding author : Payam Hacısalihoğlu