Table 1:
Baseline characteristics of patients.
| All patients (n=177) | ctDNA T790M detected (n=56) | ctDNA T790M not detected (n=121) | |
|---|---|---|---|
| Age (y, range) | 66 (38 – 91) | 66 (38 – 91) | 66 (42 – 90) |
| Sex (%) | |||
| Female | 115 (65) | 35 (62) | 80 (66) |
| Male | 62 (35) | 21 (38) | 41 (34) |
| Smoking status (%) | |||
| Never | 93 (53) | 31 (55) | 62 (51) |
| Ever | 84 (47) | 25 (45) | 59 (49) |
| EGFR-mutant allele (%) | |||
| exon 21 | 59 (33) | 17 (30) | 42 (35) |
| exon 19 | 107 (60) | 37 (66) | 70 (58) |
| exon 18 | 11 (6) | 2 (4) | 9 (7) |
| Initial EGFR-TKI (%) | |||
| Erlotinib | 155 (88) | 53 (95) | 102 (84) |
| Afatinib | 13 (7) | 2 (4) | 11 (9) |
| Gefitinib | 3 (2) | 1 (1) | 2 (2) |
| Third-generationa | 6 (3) | 0 | 6 (5) |
| Median time EGFR-TKI to T790M ctDNA testing (y) | 1.4 | 1.4 | 1.4 |
Abbreviation: y, years; ctDNA, circulating-tumor DNA; TKI, tyrosine-kinase inhibitor.
a
Osimertinib (n=4), Rociletinib (n=1), Nazartinib (n=1)