Table 5 Univariate and multivariate analyses of progression-free survival according to clinical and treatment characteristics
Characteristics | Patients, No. (%) | mPFS (months) | Univariate analysis | Multivariate analysis | ||
|---|---|---|---|---|---|---|
HR (95% CI) | p-value | HR (95% CI) | p-value | |||
EGFR mutation subtype, No. (%) | ||||||
 Exon 19 deletion | 68 (80.0) | 16.0 | 0.31 (0.14–0.71)a | 0.006 | 0.27 (0.12–0.58)a | 0.001 |
 Exon 21 L858R point mutation | 11 (12.9) | 8.7 | 0.34 (0.13–0.94)b | 0.037 | 0.39 (0.15–1.03)b | 0.058 |
 Rare and complex mutation | 6 (7.1) | 9.0 |  |  |  |  |
Baseline symptomatic brain metastases, No. (%) | ||||||
 No | 60 (70.6) | 14.3 | 0.67 (0.34–1.27)g | 0.209 | 0.70 (0.37–1.32)g | 0.267 |
 Yes | 25 (29.4) | 13.5 |  |  |  |  |
ECOG performance status, No. (%) | ||||||
 0–1 | 69 (81.2) | 13.8 | 0.86 (0.39–1.90)g | 0.703 | 0.86 (0.39–1.90)g | 0.703 |
 2–4 | 16 (18.8) | 15.9 |  |  |  |  |
Abnormal organ function, No. (%) | ||||||
 No | 70 (82.4) | 14.3 | 0.53 (0.25–1.09)g | 0.086 | 0.50 (0.25–1.00)g | 0.050 |
 Yes | 15 (17.6) | 8.8 |  |  |  |  |
Afatinib dose adjustment, No. (%) | ||||||
 Dose reduced | 26 (30.6) | 15.9 | 0.93 (0.44–1.99)c | 0.854 | 0.72 (0.39–1.34)c | 0.301 |
 Dose increased | 10 (11.8) | 13.5 | 2.35 (0.86–6.47)d | 0.098 | 2.13 (0.93–4.88)d | 0.075 |
 Starting dose maintained | 49 (57.6) | 13.4 |  |  |  |  |
Optimal afatinib dose, No. (%) | ||||||
 Less than 40 mg once daily | 51 (60.0) | 15.9 | 0.64 (0.32–1.28)e | 0.209 | 0.47 (0.21–1.08)e | 0.075 |
 50 mg once daily | 4 (4.7) | 13.5 | 0.97 (0.25–3.78)f | 0.962 | 1.03 (0.27–4.01)f | 0.962 |
 40 mg once daily | 30 (35.3) | 13.4 |  |  |  |  |