Table 1.
Clinical characteristics of patients in DFCI EGFR cohort.
| Cohort Characteristics | Pretreatment Cohort | |
|---|---|---|
| Characteristic | No. (%) | No. (%) |
| No of patients | 269 | 189 |
| Med age at diagnosis | 62 (29–93) | 64 (29–93) |
| Sex | ||
| Male | 79 (30) | 57 (30) |
| Female | 190 (70) | 132 (70) |
| Smoking status | ||
| Ever | 106 (40) | 80 (42) |
| Never | 163 (60) | 109 (58) |
| EGFR mutation | ||
| Exon 19 deletion | 137 (51) | 92 (49) |
| L858R | 103 (38) | 74 (39) |
| Other | 29 (11) | 23 (12) |
| Stage at diagnosis | ||
| I, II | 37 (14) | 29 (15) |
| III | 22 (8) | 15 (8) |
| IVa | 69 (26) | 52 (28) |
| IVb | 141 (52) | 93 (49) |
| Line of therapy, first TKI | ||
| First | 226 (84) | 162 (86) |
| Second | 39 (14) | 24 (13) |
| Third or higher | 4 (1) | 3 (1) |
| 1st TKI | ||
| Erlotinib | 255 (94) | 178 (94) |
| Afatinib | 9 (3) | 7 (4) |
| Gefitinib, Icotinib | 3 (1) | 2 (1) |
| Osimertinib | 2 (1) | 2 (1) |
| 1st-line Resistance mechanism assessed | 124 (46) | 67 (35) |
| T790M mutation | 98 | 55 |
| Bypass pathway | 7 | 5 |
| Small cell transformation | 5 | 2 |
| Other/not detected | 14 | 5 |
| Received osimertinib after TKI resistance | 94 (35) | 50 (26) |
| Osimertinib Resistance mechanism assessed | 8 | 3 |
| C797S mutation | 4 | |
| Small cell transformation | 4 | 3 |
| Other/not detected | 1 | |