Prognostic Variables for Local Recurrence and Overall Survival after Surgical Treatment of Sacral Chordoma: An Analysis from AOSpine Tumor Knowledge Forum Primary Spinal Tumor Retrospective Database
Bibliographic record
Abstract
Introduction Sacral chordomas are rare, locally invasive, malignant neoplasms. Although, their surgical and oncological therapy has changed significantly over the last few decades, the prognosis is still poor. The objective of this study was to identify factors that have an impact on the overall and local recurrence-free survival of patients with sacral chordoma. Materials and Methods Utilizing the AOSpine Knowledge Forum Tumor multicenter ambispective database, surgically treated sacral chordoma cases were identified. Kaplan–Meier, log-rank test, and Cox regression modeling were used to assess the effect of several pre-, peri-, and postoperative variables on overall survival and local recurrence-free survival. Results A total of 167 patients with surgically treated sacral chordoma were identified. The male/female ratio was 98:69 with a mean age of 57 years (SD = 15) at the time of surgery (18–89 years). The local recurrence occurred in 35% ( n = 57) and death occurred in 30% of the patients ( n = 50) during the study period (5 days–16.2 years). The median overall survival was 6 years postsurgery and local recurrence-free survival was 4 years. In the univariate analysis, age ( p < 0.001) and preoperative motor deficit ( p = 0.003) were significantly associated with poor overall survival, and nerve root sacrifice showed a trend toward significance ( p = 0.088). Previous tumor surgery at the same site ( p = 0.002), intralesional resection ( p < 0.001), and tumor volume ( p = 0.030) were significantly associated with local recurrence. In the multivariate models, age and motor deficit were associated with poor survival, while previous surgery and intralesional resection were significantly related to local recurrence. Conclusion This study identifies two predictive variables for mortality (age and impaired motor function) and two for local recurrence (previous tumor surgery and intralesional surgery) in surgically treated sacral chordoma.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| 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".