Table 2.
Univariate and Multivariate Analyses of Survival After Transformation
| Survival After Transformation, Grade III Tumors Only | ||||||
|---|---|---|---|---|---|---|
| Univariate | Multivariate | |||||
| Hazard Ratio | 95% CI | P Value | Hazard Ratio | 95% CI | P Value | |
| Subtype | ||||||
| IDH-mutant 1p/19q co-deleted oligodendroglioma | 1 | Reference | - | 1 | Reference | - |
| IDH-mutant astrocytoma | 1.27 | 0.55-2.95 | 0.58 | 2.56 | 0.84-7.76 | 0.098 |
| Hypermutation | ||||||
| Non-HM | 1 | Reference | - | 1 | Reference | - |
| HM | 2.32 | 1.00-5.40 | 0.051 | 3.42 | 1.18-9.92 | 0.024 |
| Prior RT | ||||||
| No prior RT | 1 | Reference | - | 1 | - | Reference |
| Prior RT | 2.8 | 1.20-6.54 | 0.018 | 3.33 | 1.36-8.13 | 0.0084 |
| Age at transformation (per year increase) | 1.03 | 0.99-1.08 | 0.16 | 1.03 | 0.98-1.10 | 0.34 |
| Time to transformation (per year increase) | 0.963 | 0.86-1.08 | 0.51 | |||
| KPSa | 0.95 | 0.92-0.99 | 0.024 | |||
| Extent of resection | ||||||
| STR or biopsy | 1 | Reference | - | |||
| GTR | 1.05 | 0.24-4.52 | 0.95 | |||
| CDKN2A status | ||||||
| No homozygous deletion | 1 | Reference | - | |||
| Homozygous deletion | 1.65 | 0.38-7.10 | 0.51 | |||
| Survival After Transformation, All Transformed Tumors | ||||||
| Univariate | ||||||
| Hazard Ratio | 95% CI | P Value | ||||
| Subtype | ||||||
| IDH-mutant 1p/19q co-deleted oligodendroglioma | 1 | Reference | - | |||
| IDH-mutant astrocytoma | 2.45 | 1.23-4.86 | .011 | |||
| Hypermutation | ||||||
| Non-HM | 1 | Reference | - | |||
| HM | 2.15 | 1.14-4.04 | .018 | |||
| Grade III vs IV | ||||||
| Grade III | 1 | Reference | - | |||
| Grade IV | 6.05 | 2.92-12.52 | <.0001 | |||
| Prior RT | ||||||
| No prior RT | 1 | Reference | - | |||
| Prior RT | 1.83 | 0.97-3.43 | .061 | |||
| Age at transformation (per year increase) | 1.03 | 0.70-1.34 | .85 | |||
| Time to transformation (per year increase) | 0.95 | 0.87-1.03 | .21 | |||
| KPSa | 0.96 | 0.93-0.99 | .017 | |||
| Extent of resection | ||||||
| STR or biopsy | 1 | Reference | - | |||
| GTR | 0.75 | 0.23-2.46 | .64 | |||
| CDKN2A status | ||||||
| No homozygous deletion | 1 | Reference | - | |||
| Homozygous deletion | 0.72 | 0.42-4.51 | .59 | |||
Abbreviations: GTR, gross total resection of enhancing and non-enhancing disease; HM, hypermutated; IDH, isocitrate dehydrogenase; KPS, Karnofsky performance status; RT, radiation therapy; STR, subtotal resection of enhancing and non-enhancing disease.
aKPS not included in multivariable models because of missing data (n = 33).