Table 3.
Factors associated with progression-free survival.
| Variables | Univariate | Multivariable Model 1 | Multivariable Model 1R | Multivariable Model 2 | Multivariable Model 2R |
|---|---|---|---|---|---|
| OP (vs. no OP) | 0.90 [0.63–1.28] | ||||
| RT (vs. no RT) | 0.93 [0.66–1.30] | ||||
| OP or RT (vs. no OP or RT) | 0.89 [0.65–1.23] | 0.81 [0.56–1.15] | 0.79 [0.55–1.16] | ||
| EGFR TKI: (vs. gefitinib) | |||||
| Erlotinib | 0.75 [0.48–1.16] | 0.75 [0.44–1.27] | 0.79 [0.50–1.23] | 0.73 [0.42–1.27] | 0.76 [0.49–1.19] |
| Afatinib | 0.54 [0.33–0.88] * | 0.52 [0.31–0.89] * | 0.53 [0.32–0.87] * | 0.51 [0.30–0.88] * | 0.51 [0.31–0.84] ** |
| Osimertinib | 0.10 [0.01–0.75] * | 0.11 [0.01–0.83] * | 0.11 [0.01–0.81] * | 0.10 [0.01–0.77] * | 0.11 [0.02–0.83] * |
| Anti-VEGF treatment (vs. no anti-VEGF) | 0.81 [0.36–1.83] | 0.86 [0.37–2.00] | 0.94 [0.40–2.22] | ||
| Male (vs. female) | 1.54 [1.09–2.17] * | 1.52 [1.07–2.17] * | 1.50 [1.06–2.11] * | 1.64 [1.13–2.39] ** | 1.57 [1.11–2.23] * |
| Age (≥65 vs. <65) | 0.83 [0.60–1.15] | 0.82 [0.57–1.18] | 0.87 [0.60–1.27] | ||
| ECOG PS (≥2 vs. ≤1) | 0.74 [0.46–1.20] | 0.81 [0.48–1.35] | 0.86 [0.51–1.45] | ||
| Exon 19 deletion vs. L858R | 0.99 [0.72–1.36] | 0.87 [0.61–1.23] | 0.94 [0.67–1.34] | ||
| PD–L1 ≥ 1% vs. PD-L1 < 1% or not tested | 1.00 [0.72–1.40] | 1.04 [0.71–1.51] | 1.14 [0.77–1.68] | ||
| Number of brain metastases (≥5 vs. <5) | 0.87 [0.62–1.22] | 1.00 [0.70–1.43] | 1.02 [0.70–1.48] | ||
| Extracranial metastasis (vs. no) | 1.26 [0.80–1.99] | 1.47 [0.91–2.38] | 1.40 [0.89–2.22] | ||
| Lung metastasis (vs. no) | 1.12 [0.81–1.54] | 0.97 [0.67–1.39] | |||
| Pleural metastasis/effusion (vs. no) | 1.29 [0.93–1.79] | 1.48 [0.98–2.23] | 1.38 [0.99–1.92] | ||
| Bone metastasis (vs. no) | 1.57 [1.12–2.21] ** | 1.66 [1.14–2.42] ** | 1.59 [1.13–2.23] ** | ||
| Liver metastasis (vs. no) | 0.99 [0.61–1.61] | 0.94 [0.55–1.60] | |||
| Pericardial metastasis/effusion (vs. no) | 1.16 [0.80–1.67] | 0.93 [0.58–1.49] | |||
| Adrenal metastasis (vs. no) | 0.99 [0.59–1.64] | 0.87 [0.49–1.55] | |||
| Other site metastasis (vs. no) | 0.97 [0.48–1.99] | 1.35 [0.61–2.98] |
Abbreviations: ECOG, Eastern Cooperative Oncology Group; EGFR, epidermal growth factor receptor; OP, surgery for brain tumor; PD-L1, programmed death ligand 1; PS, performance status; RT, radiotherapy for brain tumor; TKI, tyrosine kinase inhibitor; VEGF, vascular endothelial growth factor. A patient with cancer harboring both the exon 19 deletion and L858R was included in the exon 19 deletion group. Data are presented as hazard ratio (HR) with 95% confidence interval. After building the maximal models of multivariable Cox regression (models 1 and 2), the corresponding reduced multivariable Cox regression models (models 1R and 2R, respectively) were built using backward variable selection, retaining only variables with p-values < 0.15. * p-value < 0.05; ** p-value < 0.01.