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.