Table 2.
Predicting factors for concordant EGFR mutation detected in liquid/tissue biopsy.
| Variables | Univariate Analysis | Multivariable Analysis—Maximal Model | Multivariable Analysis—Reduced Model † | |||
|---|---|---|---|---|---|---|
| OR (95% CI) | p Value | OR (95% CI) | p Value | OR (95% CI) | p Value | |
| Male (vs. female) | 1.49 (0.42–5.19) | 0.5354 | 1.83 (0.28–12.11) | 0.5296 | ||
| Age ≥65 (vs. <65) | 0.96 (0.30–3.05) | 0.9448 | 1.46 (0.19–11.27) | 0.7161 | ||
| ECOG ≥2 (vs. ≤1) | 0.25 (0.02–2.97) | 0.2722 | 0.06 (0.00–21.15) | 0.3423 | ||
| T3–4 (vs. T1–2) | 2.25 (0.60–8.42) | 0.2286 | 10.48 (0.87–126.59) | 0.0645 | 5.45 (0.98–30.24) | 0.0527 |
| N1–3 (vs. N0) | 7.07 (1.93–25.85) | 0.0031 | 10.06 (1.28–78.79) | 0.0280 | 8.71 (1.88–40.35) | 0.0057 |
| Brain metastasis (with vs. without) | 9.71 (1.15–82.39) | 0.0371 | 5.87 (0.36–96.65) | 0.2153 | ||
| Lung metastasis (with vs. without) | 0.71 (0.22–2.30) | 0.5728 | 0.31 (0.04–2.47) | 0.2666 | ||
| Bone metastasis (with vs. without) | 7.69 (1.85–31.91) | 0.0049 | 8.15 (0.99–66.95) | 0.0510 | 9.65 (1.72–54.05) | 0.0099 |
| Pleural metastasis (with vs. without) | 1.20 (0.38–3.79) | 0.7561 | 0.49 (0.06–3.80) | 0.4954 | ||
| Liver metastasis (with vs. without) | 3.04 (0.33–28.23) | 0.3291 | 5.26 (0.29–96.02) | 0.2630 | ||
| Pericardial metastasis (with vs. without) | 4.57 (0.52–40.56) | 0.1721 | 0.99 (0.04–22.00) | 0.9943 | ||
| Adrenal metastasis (with vs. without) | 3.04 (0.33–28.23) | 0.3291 | 3.85 (0.19–78.24) | 0.3808 | ||
| Metastasis to other sites (with vs. without) | ‡ | ‡ | ||||
Abbreviations: EGFR = epidermal growth factor receptor; OR = odds ratio; CI = confidence interval; ECOG = Eastern Cooperative Oncology Group. † Reduced multivariable models were developed with backward variable selection method, keeping only variables with p value less than 0.1, from the maximal model. ‡ Because all cases with metastasis to other sites were in the concordant group, odds ratio could not be estimated. This variable was therefore not included in the models.