Significance of necrosis in grading of anaplastic oligodendroglial tumors: A clinicopathological and genetic study of 916 high-grade gliomas
Bibliographic record
Abstract
1502 Background: High-grade gliomas (HGG, WHO grades III-IV) are morphologically and genetically diverse, with survivals ranging from months to decades. Although WHO 2000 grading criteria are well established for pure astrocytomas [anaplastic astrocytoma (AA) and glioblastoma (GBM)], those for oligodendroglial neoplasms [anaplastic oligoastrocytoma (AOA) and oligodendroglioma (AO)] remain subjective, there being a debate regarding the existence of a grade IV variant based on the finding of necrosis, particularly with pseudopalisading (PPN). Methods: Overall survival of 916 adult (>20 yr) patients diagnosed between 1990 and 2005 with supratentorial HGG (77 AA, 481 GBM, 183 AOA, 175 AO) was analyzed by uni- (log-rank) and multivariate (Cox proportional hazards) models for significance of the following factors: microvascular proliferation, necrosis, patient age, surgery (stereotactic vs. open), location, primary vs. secondary tumor, year of diagnosis, and chromosome 1p and 19q losses by fluorescence in situ hybridization. Results: Necrosis was a statistically significant predictor of poor survival on multivariate analyses in AOA (P=0.035), but not in AO (log-rank P=0.048, Cox P=0.9), while PPN showed a trend towards significance on multivariate analysis only in AOA (P=0.096). Other independent predictors on multivariate analysis included age, grade, surgery type, and year of diagnosis for AA/GBM and age, primary tumor, and 1p/19q codeletion for both AOA and AO (P<0.05). Median survival for AOA patients whose tumors featured necrosis (20.7 mo) was significantly worse than their counterparts lacking necrosis (>104 mo); survival of the latter was more similar to that of AO (83.5 mo), whereas in the former it was better than GBM (10.5 mo) (log-rank P<0.0001). Conclusions: Stratification of oligoastrocytomas, but not of pure oligodendrogliomas, into grades III (AOA) and IV (GBM with oligodendroglial features) on the basis of necrosis is prognostically justified and is more accurate than the current approach of using a single anaplastic grade. These data provide impetus for the modification of present WHO criteria. No significant financial relationships to disclose.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".