Table 3. Results of EGFR mutation status recheck in part of patients with objective response to erlotinib treatment.
| Demographic data | Cross recheck of EGFR mutations | Efficacy of erlotinib | ||||||
| Pt | Age | Gender | Smoking | ECOG | Method | Result | Prior C/T | PFS (m) |
| Direct sequencing group | ||||||||
| D1 | 82 | M | CS | 1 | MS | Del E746_A750 | 1 | 8.6 |
| D2 | 60 | M | NS | 1 | MS | Del E746_A750 | 0 | 12.8 |
| D3 | 61 | M | FS | 1 | MS | Unfound | 1 | 5.0 |
| D4 | 73 | F | NS | 3 | MS | Unfound | 0 | 15.5b |
| D5 | 77 | M | NS | 1 | MS | Unfound | 1 | 11.0 |
| D6 | 82 | M | FS | 2 | MS | Unfound | 1 | 2.9b |
| D7 | 84 | M | NS | 2 | MS | Unfound | 0 | 5.8b |
| D8 | 64 | F | NS | 2 | MS | Del E746_A750/T790M | 0 | 5.3b |
| D9 | 82 | M | CS | 2 | MS | L858R | 1 | 5.1b |
| D10 | 49 | F | NS | 1 | MS | L858R/T790M | 2 | 8.4 |
| Sensitive method group | ||||||||
| S1 | 77 | F | NS | 1 | DS | Del L747_T751>N | 1 | 13.1b |
| S2 | 73 | M | FS | 1 | DS | Del K745_A750>R | 1 | 2.4b |
| S3 | 58 | F | NS | 2 | DS | Del E746_T751>VP | 1 | 5.1 |
| S4 | 62 | F | NS | 3 | DS | Del L747_A750>Pa | 3 | 6.5 |
| S5 | 61 | F | NS | 1 | DS | I706T | 2 | 7.9 |
| S6 | 65 | F | NS | 1 | DS | Wild type | 1 | 7.7 |
| S7 | 77 | M | CS | 1 | DS | Wild type | 0 | 6.9 |
| S8 | 65 | M | NS | 2 | DS | Wild type | 2 | 4.1b |
| S9 | 59 | F | NS | 1 | DS | Wild type | 1 | 10.1 |
EGFR, epidermal growth factor receptor; ECOG, Eastern Cooperative Oncology Group performance status; C/T, chemotherapy; PFS, progression-free survival; CS, current smoker; FS, former smoker; NS, non-smoker; MS, matrix-assisted laser desorption ionization-time of flight mass spectrometry; DS, direct sequencing.
a
EGFR mutation status of patient S4 was analyzed as wild type by PNA-LNA PCR clamp in September 2011 and our facility was able to detect Del L747_A750>P since September 2013 by adding new mutation detection probes.
b
Still under erlotinib treatment without progression.