Table 4.
Factors associated with overall survival.
| Variables | Univariate | Multivariable Model 3 | Multivariable Model 3R | Multivariable Model 4 | Multivariable Model 4R |
|---|---|---|---|---|---|
| OP (vs. no OP) | 0.80 [0.53–1.21] | ||||
| RT (vs. no RT) | 0.81 [0.55–1.19] | ||||
| OP or RT (vs. no OP or RT) | 0.80 [0.55–1.17] | 0.89 [0.60–1.33] | 0.87 [0.57–1.33] | ||
| EGFR TKI: (vs. gefitinib) | |||||
| Erlotinib | 0.91 [0.56–1.46] | 0.83 [0.48–1.43] | 0.88 [0.54–1.42] | 0.87 [0.48–1.56] | 0.85 [0.52–1.39] |
| Afatinib | 0.63 [0.37–1.08] | 0.61 [0.34–1.10] | 0.63 [0.37–1.08] | 0.65 [0.36–1.19] | 0.63 [0.37–1.08] |
| Osimertinib | † | † | † | † | † |
| Anti-VEGF treatment (vs. no anti-VEGF) | 0.28 [0.04–1.99] | 0.35 [0.05–2.53] | 0.30 [0.04–2.24] | ||
| Male (vs. female) | 1.52 [1.03–2.26] * | 1.57 [1.04–2.36] * | 1.63 [1.09–2.44] * | 1.53 [1.00–2.34] * | 1.54 [1.03–2.29] * |
| Age (≥65 vs. <65) | 1.32 [0.91–1.91] | 1.43 [0.95–2.14] | 1.45 [0.99–2.12] | 1.48 [0.98–2.24] | 1.42 [0.97–2.08] |
| ECOG PS (≥2 vs. ≤1) | 0.72 [0.38–1.34] | 0.70 [0.36–1.37] | 0.65 [0.34–1.22] | 0.81 [0.41–1.59] | |
| Exon 19 deletion vs. L858R | 1.10 [0.76–1.59] | 1.10 [0.74–1.64] | 1.18 [0.79–1.77] | ||
| PD–L1 ≥ 1% vs. PD-L1 < 1% or not tested | 1.17 [0.79–1.72] | 1.20 [0.78–1.84] | 1.20 [0.77–1.88] | ||
| Number of brain metastases (≥5 vs. <5) | 0.88 [0.60–1.30] | 0.97 [0.63–1.47] | 0.91 [0.59–1.39] | ||
| Extracranial metastasis (vs. no) | 1.69 [0.97–2.93] | 1.92 [1.08–3.43] * | 1.99 [1.14–3.49] * | ||
| Lung metastasis (vs. no) | 1.36 [0.94–1.98] | 1.23 [0.81–1.88] | |||
| Pleural metastasis/effusion (vs. no) | 1.13 [0.78–1.64] | 1.23 [0.77–1.97] | |||
| Bone metastasis (vs. no) | 1.38 [0.94–2.03] | 1.52 [0.98–2.37] | 1.43 [0.97–2.11] | ||
| Liver metastasis (vs. no) | 0.82 [0.45–1.49] | 0.66 [0.35–1.28] | |||
| Pericardial metastasis/effusion (vs. no) | 0.86 [0.56–1.32] | 0.64 [0.37–1.10] | |||
| Adrenal metastasis (vs. no) | 1.24 [0.70–2.17] | 1.19 [0.61–2.31] | |||
| Other site metastasis (vs. no) | 1.24 [0.57–2.67] | 1.07 [0.43–2.66] |
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 3 and 4), the corresponding reduced multivariable Cox regression models (models 3R and 4R, respectively) were built using backward variable selection, retaining only variables with p-values < 0.15. † HR could not be assessed due to no event in a group. * p-value < 0.05.