Table 2.
Analyses of PFS and OS for Biomarker Subsets
| Biomarker Subset | All Patients |
EGFR WT Only |
||
|---|---|---|---|---|
| Erlotinib | CP + Erlotinib | Erlotinib | CP + Erlotinib | |
| EGFR FISH positive | ||||
| No. | 37 | 35 | 23 | 27 |
| Median PFS | 2.76 | 5.06 | 2.10 | 5.29 |
| 6-month PFS rate | 39.2 | 23.4 | 27.6 | 21.7 |
| 12-month OS rate | 62.2 | 54.7 | 57.3 | 60.1 |
| EGFR FISH negative | ||||
| No. | 30 | 33 | 26 | 23 |
| Median PFS | 2.27 | 4.17 | 1.91 | 4.24 |
| 6-month PFS rate | 22.2 | 29.8 | 22.0 | 38.1 |
| 12-month OS rate | 58.3 | 38.4 | 55.5 | 49.5 |
| P for PFS of positive v negative* | .075 | .778 | .492 | .652 |
| KRAS mutation | ||||
| No. | 13 | 15 | 11 | 12 |
| Median PFS | 2.23 | 2.96 | 2.23 | 2.30 |
| 6-month PFS rate | 11.5 | 8.6 | NC | 11.4 |
| 12-month OS rate | 40.4 | 53.3 | 47.7 | 58.3 |
| KRAS WT | ||||
| No. | 51 | 51 | 38 | 38 |
| Median PFS | 3.15 | 4.90 | 1.97 | 5.36 |
| 6-month PFS rate | 38.2 | 31.7 | 27.3 | 33.9 |
| 12-month OS rate | 63.1 | 44.3 | 57.9 | 53.5 |
| P for PFS of mutated v WT* | .078 | .078 | .550 | .092 |
| E-cadherin positive: high | ||||
| No. | 25 | 21 | 19 | 15 |
| Median PFS | 2.76 | 4.90 | 2.69 | 5.52 |
| 6-month PFS rate | 28.0 | 21.4 | 21.1 | 31.4 |
| 12-month OS rate | 58.8 | 53.1 | 55.9 | 65.2 |
| E-cadherin negative: low | ||||
| No. | 22 | 26 | 18 | 21 |
| Median PFS | 1.54 | 5.06 | 1.45 | 5.06 |
| 6-month PFS rate | 33.2 | 31.0 | 24.2 | 27.3 |
| 12-month OS rate | 75.6 | 31.4 | 69.6 | 34.4 |
| P for PFS of high v low* | .794 | .725 | .495 | .836 |
| Vimentin positive: high | ||||
| No. | 20 | 12 | 15 | 8 |
| Median PFS | 1.48 | 5.78 | 1.41 | 6.01 |
| 6-month PFS rate | 27.1 | 41.6 | 7.5 | 53.6 |
| 12-month OS rate | 58.2 | 50.3 | 50.3 | 75.0 |
| Vimentin negative: low | ||||
| No. | 28 | 33 | 22 | 27 |
| Median PFS | 2.50 | 4.90 | 2.27 | 5.29 |
| 6-month PFS rate | 27.5 | 22.0 | 26.0 | 23.1 |
| 12-month OS rate | 66.5 | 38.7 | 66.1 | 41.6 |
| P for PFS of high v low* | .757 | .163 | .287 | .058 |
Abbreviations: PFS, progression-free survival; OS, overall survival; WT, wild type; CP, carboplatin/paclitaxel; FISH, fluorescent in situ hybridization; NC, not calculated.
*
P values are from the log-rank test comparing the erlotinib and CP + erlotinib curves.