Table 2.
Cox regression analysis of overall survival according to per-protocol receipt of whole brain radiotherapy
| Parameter | Hazard ratio | [95% CI] | P |
|---|---|---|---|
| Whole brain radiotherapya | |||
| Before extracranial progression | 0.70 | [0.45–1.11] | 0.133 |
| After extracranial progression | 1.20 | [0.89–1.61] | 0.214 |
| Age (continuous) | 1.02 | [1.01–1.04] | <0.001 |
| Extracranial progression | 4.51 | [3.03–6.72] | <0.001 |
| Local therapy | |||
| Radiosurgery | 1.00 | Referent | – |
| Surgery | 0.86 | [0.66–1.14] | 0.293 |
| ECOG performance status | |||
| 0 | 1.00 | Referent | – |
| 1 | 1.08 | [0.83–1.40] | 0.571 |
| 2 | 1.70 | [1.13–2.55] | 0.011 |
| Primary site lung (versus other) | 1.32 | [1.02–1.70] | 0.033 |
| Number of metastases (2–3 versus 1) | 1.09 | [0.79–1.49] | 0.609 |
| Macroscopic tumor present outside brain | |||
| Absent | 1.00 | Referent | – |
| Present | 1.10 | [0.84–1.44] | 0.490 |
| Unknown | 1.64 | [0.83–3.24] | 0.154 |
Extracranial progression was included as a time-dependent covariate.
a
Reference group = arms randomized to no whole brain radiotherapy.