Table 3. Univariate and Multivariable Analyses of the Clinicopathological Factors Associated With Overall Survival.
| Characteristic | No. of Patients (n = 139) | No. of Events (n = 50) | Overall Survival, Median (95% CI), mo | P Value | HR (95% CI) | P Value |
|---|---|---|---|---|---|---|
| Sex | ||||||
| Male | 48 | 15 | 25.7 (18.4-32.9) | .44 | NA | NA |
| Female | 91 | 35 | 20.6 (14.8-26.4) | |||
| Age, y | ||||||
| <60 | 76 | 24 | 30.7 (20.8-40.7) | .10 | 1.76 (0.90-3.30) | .06 |
| ≥60 | 63 | 26 | 19.1 (10.4-21.8) | |||
| Tobacco exposure | ||||||
| Absent | 101 | 39 | 20.9 (17.8-24.2) | .21 | 0.74 (0.40-1.50) | .40 |
| Present | 38 | 11 | 23.7 (NR) | |||
| Wood smoke exposure | ||||||
| Absent | 87 | 30 | 23.7 (17.3-30.0) | .75 | NA | NA |
| Present | 52 | 20 | 20.5 (18.1-22.8) | |||
| Predominant histological pattern | ||||||
| Well/moderately differentiated | 56 | 20 | 25.7 (NR) | .17 | 0.75 (0.40-1.40) | .36 |
| Poorly/nondifferentiated | 83 | 30 | 20.6 (17.6-23.6) | |||
| Metastases | ||||||
| Bone | ||||||
| Absent | 82 | 32 | 21.5 (17.4-25.7) | .58 | NA | NA |
| Present | 57 | 18 | 25.7 (13.4-37.9) | |||
| Pleura | ||||||
| Absent | 92 | 33 | 22.5 (18.7-26.2) | .97 | NA | NA |
| Present | 47 | 17 | NR (NR) | |||
| Contralateral lung | ||||||
| Absent | 92 | 35 | 20.9 (17.7-24.3) | .59 | NA | NA |
| Present | 47 | 15 | 31.7 (13.1-50.3) | |||
| Adrenal glands | ||||||
| Absent | 130 | 47 | 22.5 (17.9-22.0) | .69 | NA | NA |
| Present | 9 | 3 | NR (NR) | |||
| Central nervous system | ||||||
| Absent | 86 | 27 | 25.7 (16.6-34.7) | .35 | NA | NA |
| Present | 53 | 23 | 20.5 (16.5-24.3) | |||
| Liver | ||||||
| Absent | 130 | 45 | 22.5 (16.0-28.9) | .33 | NA | NA |
| Present | 9 | 5 | 20.9 (0.0-48.5) | |||
| EGFR mutational profile | ||||||
| Exon 18, G719X | 5 | 0 | NA | .23 | NA | NA |
| Exon 19, deletion | 89 | 33 | 20.9 (11.2-30.7) | |||
| Exon 21, L858R | 45 | 17 | 20.6 (10.3-NR) | |||
| EGFR-TKIs treatment | ||||||
| Gefitinib | 50 | 21 | 17.5 (10.4-24.6) | .27 | NA | NA |
| Afatinib dimaleate | 63 | 19 | 25.7 (17.9-33.3) | |||
| Erlotinib hydrochloride | 26 | 10 | 23.7 (18.3-28.9) | |||
| Objective response rate | ||||||
| Responders | 87 | 24 | 31.7 (17.0-46.3) | .001 | NA | NA |
| Nonresponders | 52 | 26 | 16.9 (9.6-24.3) | |||
| Disease control rate | ||||||
| Responders | 133 | 45 | 22.5 (17.6-23.4) | .02 | 2.48 (0.90-7.10) | .09 |
| Nonresponders | 6 | 5 | 5.5 (0.0-19.3) | |||
| Treatment arm | ||||||
| EGFR-TKIs | 70 | 32 | 17.5 (11.4-23.7) | .02 | 0.52 (0.30-0.90) | .04 |
| EGFR-TKIs plus metformin | 69 | 18 | 31.7 (20.5-42.8) | |||
| LKB1 expression | ||||||
| Negative | 8 | 5 | 25.7 (13.2-38.1) | .94 | NA | NA |
| Positive | 16 | 7 | 20.5 (NR) | |||
| Second-line therapy | ||||||
| Absent | 78 | 32 | 14.0 (11.2-22.5) | .005 | NA | NA |
| Present | 61 | 18 | 25. 7 (20.6-NR) | |||
| Third-line therapy | ||||||
| Present | 122 | 44 | 20.6 (14.6-NR) | .08 | NA | NA |
| Absent | 17 | 6 | 30.7 (18.6-NR) | |||
Abbreviations: EGFR-TKIs, epidermal growth factor receptor–tyrosine kinase inhibitors; HR, hazard ratio; LKB1, liver kinase 1; NA, not applicable; NR, not reached.