Table 3.
Multivariable Cox regression analyses showing the association between each factor and overall or progression-free survival, including the VeriStrat test as a prognostic biomarker.
| Factor | Overall survival hazard ratio (95% CI), p-value | Progression-free survival hazard ratio (95% CI), p-value | ||
|---|---|---|---|---|
| Ignoring first-cycle rash | ||||
| VeriStrat (Good vs. Poor) | 0.58 (0.48–0.70) | <0.001 | 0.67 (0.56–0.81) | <0.001 |
| Treatment (erlotinib vs. placebo) | 0.93 (0.87–1.11) | 0.41 | 0.85 (0.71–1.02) | 0.08 |
| Age | 1.00 (0.99–1.02) | 0.74 | 1.00 (0.99–1.02) | 0.51 |
| Sex (females vs. males) | 0.82 (0.68–0.98) | 0.03 | 0.78 (0.65–0.94) | 0.009 |
| ECOG | ||||
| 0-1 | 1.0 | <0.001 | 1.0 | <0.001 |
| 2 | 1.30 (1.01–1.67) | 1.11 (0.87–1.43) | ||
| 3 | 2.04 (1.53–2.72) | 1.85 (1.39–2.47) | ||
| Stage (IV vs. IIIB) | 1.21 (1.00–1.46) | 0.04 | 1.23 (1.02–1.48) | 0.03 |
| Histology | ||||
| Squamous | 1.0 | 0.02 | 1.0 | 0.05 |
| Adenocarcinoma | 1.26 (1.02–1.55) | 1.16 (0.95–1.43) | ||
| Other | 1.34 (1.07–1.69) | 1.33 (1.06–1.68) | ||
| Smoking status | ||||
| Never/former smoker | 1.0 | 0.25 | 1.0 | 0.30 |
| Current smoker | 1.12 (0.92–1.35) | 1.10 (0.92–1.33) | ||
| EGFR (positive vs wild-type) | 0.53 (0.33–0.83) | 0.006 | 0.65 (0.42–1.01) | 0.06 |
| Allowing for first cycle rash | ||||
| VeriStrat (Good vs. Poor) | 0.61 (0.50–0.74) | <0.001 | 0.71 (0.58–0.87) | <0.001 |
| Treatment | ||||
| Placebo | 1.0 | <0.001 | 1.0 | 0.002 |
| Erlotinib, no rash | 1.29 (1.01–1.65) | 1.07 (0.84–1.37) | ||
| Erlotinib, rash | 0.76 (0.61–0.94) | 0.71 (0.57–0.89) | ||
| Age | 1.00 (0.99–1.02) | 0.67 | 1.01 (0.99–1.02) | 0.48 |
| Sex (females vs. males) | 0.83 (0.68–1.01) | 0.06 | 0.82 (0.67–0.99) | 0.04 |
| ECOG | ||||
| 0-1 | 1.0 | 0.001 | 1.0 | 0.004 |
| 2 | 1.26 (0.97–1.63) | 1.07 (0.83–1.38) | ||
| 3 | 1.75 (1.28–2.38) | 1.55 (1.14–2.11) | ||
| Stage (IV vs. IIIB) | 1.29 (1.06–1.57) | 0.01 | 1.31 (1.07–1.59) | 0.008 |
| Histology | ||||
| Squamous | 1.0 | 0.10 | 1.0 | 0.22 |
| Adenocarcinoma | 1.20 (0.96–1.51) | 1.10 (0.88–1.37) | ||
| Other | 1.28 (1.00–1.64) | 1.25 (0.97–1.60) | ||
| Smoking status | ||||
| Never/former smoker | 1.0 | 0.31 | 1.0 | 0.25 |
| Current smoker | 1.11 (0.90–1.36) | 1.13 (0.92–1.38) | ||
| EGFR (positive vs wild-type) | 0.55 (0.34–0.89) | 0.01 | 0.70 (0.44–1.11) | 0.13 |
ECOG, Eastern Cooperative Oncology Group; CI, confidence interval; EGFR, epidermal growth factor receptor; HR, hazard ratio.
Each HR is adjusted for all the other factors in the table except for EGFR status (because there were only 27 who were EGFR positive). The HRs for EGFR status are from a separate multivariable Cox regression which contains all the factors in the table.