Table 1.
Patient Clinical Characteristics
| Characteristics | First- or Second-Generation EGFR TKI Cohort, n (%) | Third-Generation EGFR TKI Cohort, n (%) | p value |
|---|---|---|---|
| Total | 31 | 31 | |
| Median age (range), y | 60 (37–89) | 58 (40–72) | 0.40 |
| Sex, n (%) | |||
| Male | 7 (23) | 8 (26) | 0.77 |
| Female | 24 (77) | 23 (74) | |
| Smoking history, n (%) | |||
| Never | 21 (68) | 16 (52) | 0.24 |
| Current and former | 9 (29) | 13 (42) | |
| NS | 1 (3) | 2 (6) | |
| Baseline driver alteration | |||
| Exon 19, deletion | 20 (65) | 24 (77) | 0.40 |
| Exon 21, L858R | 10 (32) | 7 (23) | |
| Exon 18, G719A | 1 (3) | 0 | |
| First- or second-generation EGFR TKI before resistance biopsy | |||
| Erlotinib or Gefitinib | 26 (84) | 20 (65) | 0.17 |
| Afatinib | 5 (16) | 9 (29) | |
| Third-generation EGFR TKI before resistance biopsy | |||
| Osimertinib | 0 | 31 (100) | |
| Response to TKI | |||
| CR/PR | 24 (77) | 22 (71) | 0.71 |
| SD/PD | 7 (23) | 8 (26) | |
| NS | 0 | 1 (3) | |
| Progression pattern at TKI resistance | |||
| Solitary | 19 (61) | 24 (77) | 0.23 |
| Multiple | 11 (36) | 7 (23) | |
| NS | 1 (3) | 0 | |
| Site of progression | |||
| Thoracic | 10 (32) | 19 (61) | 0.03 |
| Extrathoracic | 20 (65) | 12 (39) | |
| NS | 1 (3) | 0 | |
Missing data were excluded from the statistical analysis.
NS, not specified; TKI, tyrosine kinase inhibitor; PD, progressive disease; CR, complete response, PR, partial response.