Table 3.
Characteristics of patients with regard to T790M mutation status at disease progression (N = 75)
| Characteristics | T790M(-) (N = 33) |
T790M(+) (N = 42) |
P values |
|---|---|---|---|
| Age, y | 65.0 (58.5–73.5) | 63.5 (56.0–68.3) | 0.313 |
| Male sex | 14 (42) | 17 (41) | 0.865 |
| ECOG | |||
| 0–1 | 30 (91) | 39 (93) | 0.999 |
| ≥2 | 3 (9) | 3 (7) | |
| Smoking status | |||
| Current or former smoker | 7 (21) | 14 (33) | 0.246 |
| Never-smoker | 26 (79) | 28 (67) | |
| Stage | |||
| IIIB/IV | 30 (91) | 38 (91) | 0.999 |
| Post-operative recurrence | 3 (9) | 4 (10) | |
| EGFR mutation | |||
| L858R | 15 (46) | 18 (43) | 0.672 |
| Exon 19 deletion | 16 (49) | 23 (55) | |
| Others† | 2 (6) | 1 (2) | |
| First-line EGFR TKI | |||
| Gefitinib | 7 (21) | 8 (19) | 0.472 |
| Erlotinib | 12 (36) | 21 (50) | |
| Afatinib | 14 (42) | 13 (31) | |
| Initial presentation | |||
| Malignant pleural effusion | 11 (33) | 14 (33) | 0.999 |
| Malignant pericardial effusion | 0 (0) | 3 (7) | 0.251 |
| Brain metastasis | 11 (33) | 16 (38) | 0.670 |
| Liver metastasis | 1 (3) | 6 (14) | 0.126 |
| Bone metastasis | 18 (55) | 21 (50) | 0.696 |
| Best response to EGFR TKI | |||
| Partial response | 21 (64) | 30 (71) | 0.420 |
| Stable disease | 9 (27) | 11 (26) | |
| Progressive disease | 3 (9) | 1 (2) | |
| Time to progression, mo | 12.4 (7.1–19.9) | 13.7 (7.9–20.0) | 0.898 |
| Duration of first-line TKI, mo | 17.3 (10.1–25.4) | 17.0 (10.7–24.5) | 0.709 |
| Overall survival, mo‡ | 35.5 (23.8–56.0) | 36.2 (22.0–52.0) | 0.572 |
ECOG, Eastern Cooperative Oncology Group; EGFR, epidermal growth factor receptor; TKI, tyrosine kinase inhibitor
† G719X, L861Q, and L858R + S768I.
‡ A total of 23 patients remained alive at the end of 2021