Table 7. Univariate and multivariate analyses of TTF according to clinical and treatment characteristics (n=92).
| Characteristics | Patients, n (%)† | mTTF (months) | Univariate analysis | Multivariate analysis | |||
|---|---|---|---|---|---|---|---|
| HR (95% CI) | P value | HR (95% CI) | P value | ||||
| EGFR mutation subtype, n (%) | |||||||
| Exon 19 deletion | 55 (59.8) | 10.5 | – | – | – | – | |
| Exon 21 L858R point mutation | 23 (25.0) | 13.9 | 1.21 (0.72–2.06)‡ | 0.471‡ | 1.22 (0.72–2.06)‡ | 0.464‡ | |
| Resistant mutations | 1 (1.1) | 12.4 | 0.93 (0.12–7.26)‡ | 0.946‡ | 0.89 (0.12–6.82)‡ | 0.910‡ | |
| Rare and complex mutation | 13 (14.1) | 6.6 | 0.70 (0.36–1.37)‡ | 0.301‡ | 0.71 (0.37–1.38)‡ | 0.312‡ | |
| Baseline symptomatic brain metastases, n (%) | |||||||
| No | 56 (60.9) | 10.0 | – | – | – | – | |
| Yes | 36 (39.1) | 11.2 | 0.91 (0.56–1.47)‡ | 0.701‡ | 0.91 (0.56–1.47)‡ | 0.701‡ | |
| ECOG performance status, n (%) | |||||||
| 0–1 | 15 (16.3) | 14.0 | – | – | – | – | |
| 2–4 | 77 (83.7) | 11.1 | 2.30 (1.22–4.36)‡ | 0.010‡ | 1.75 (0.97–3.16)‡ | 0.062‡ | |
| Tumor stage, n (%) | |||||||
| IVB | 38 (41.3) | 7.9 | – | – | – | – | |
| IVA | 51 (55.4) | 12.3 | 0.86 (0.53–1.40)‡ | 0.543‡ | 0.76 (0.49–1.18)‡ | 0.219‡ | |
| IIIC | 3 (3.3) | 4.7 | 4.84 (1.35–17.37)‡ | 0.015‡ | 3.37 (1.00–11.34)‡ | 0.050‡ | |
| Comorbidities, n (%) | |||||||
| No | 59 (64.1) | 11.2 | – | – | – | – | |
| Yes | 33 (35.9) | 10.9 | 1.39 (0.86–2.25)‡ | 0.174‡ | 1.3 (0.85–2.09)‡ | 0.214‡ | |
| Afatinib starting dose, n (%) | |||||||
| 40 mg once daily | 29 (31.5) | 9.8 | – | – | – | – | |
| Less than 40 mg once daily | 63 (68.5) | 12.5 | 0.62 (0.38–1.02)‡ | 0.062‡ | 0.76 (0.49–1.20)‡ | 0.238‡ | |
| Afatinib dose adjustment, n (%) | |||||||
| No | 67 (72.8) | 11.1 | – | – | – | – | |
| Yes | 25 (27.2) | 11.2 | 0.77 (0.47–1.26)‡ | 0.301‡ | 0.77 (0.48–1.26)‡ | 0.307‡ | |
†, number and percentage of subgroup of patients who failed treatment with afatinib; ‡, the first group was the reference category in logistic regression analysis. mTTF, median time to treatment failure; HR, hazard ratio; CI, confidence interval; EGFR, epidermal growth factor receptor; ECOG, Eastern Cooperative Oncology Group.