Predictive factors for overall and progression-free survival, and dissemination in oligodendroglial tumors.

The pattern of recurrence and predictive factors for tumor progression, dissemination and survival in oligodendroglial tumors were investigated. 56 consecutive patients with oligodendroglial tumors were retrospectively analyzed to determine the predictive significance of various factors, including World Health Organization grade, loss of chromosomes 1p and 19q, and immunohistochemical features of TP53, O(6)-methylguanine-deoxyribonucleic-acid-methyltransferase, CD44H, nestin, and Ki-67. Eleven patients developed dissemination, and had significantly shorter post-progression survival compared to ten patients with local recurrence. Univariate analysis showed that retention of chromosome 1p or 19q, Ki-67 labeling index > or = 25%, diffuse expression of nestin, and p53 labeling index > or = 10% were unfavorable factors for overall, progression-free, and dissemination-free survival. Multivariate analysis showed that Ki-67 labeling index > or = 25% and diffuse expression of nestin were significant for dissemination-free survival. In conclusion, post-progression survival shows significant differences between patients with local and disseminated recurrence. Ki-67 labeling index and nestin expression pattern are useful markers to predict dissemination.