Table 4 Cox regression analyses for the factors predicting progression-free survival (PFS3) and overall survival (OS3) with the third-line treatment
Clinical features | Progression-free survival with the third-line treatment (PFS3) | Overall survival with the third-line treatment (OS3) | ||
|---|---|---|---|---|
Univariate analysis | Multivariable analysis | Univariate analysis | Multivariable analysis | |
All study cohort | ||||
 Sex (male vs. female) | 0.80 [0.44 - 1.45] | 0.94 [0.50 - 1.79] | 0.61 [0.29 - 1.28] | 0.70 [0.32 - 1.51] |
 Age (≥65 vs. <65 years old) | 0.80 [0.44 - 1.46] | 0.78 [0.43 - 1.42] | 3.09 [1.52 - 6.28] | 5.97 [2.65 - 13.44] |
 Performance status while starting the third-line treatment (ECOG ≥2 vs. ≤1) | 2.08 [1.18 - 3.66] | 2.21 [1.20 - 4.07] | 3.30 [1.64 - 6.64] | 5.84 [2.61 - 13.09] |
 The third-line treatment (erlotinib vs. cytotoxic chemotherapy) | 0.96 [0.55 - 1.68] | 0.79 [0.43 - 1.44] | 1.25 [0.65 - 2.40] | 0.82 [0.41 - 1.64] |
Patients receiving cytotoxic chemotherapy as the third-line treatment | ||||
 Sex (male vs. female) | 1.01 [0.44 - 2.34] | 1.57 [0.51 - 4.81] | 0.93 [0.33 - 2.59] | 1.21 [0.35 - 4.19] |
 Age (≥65 vs. <65 years old) | 0.57 [0.24 - 1.36] | 0.62 [0.22 - 1.71] | 3.10 [1.11 - 8.69] | 4.79 [1.40 - 16.41] |
 Performance status while starting the third-line treatment (ECOG ≥2 vs. ≤1) | 2.00 [0.93 - 4.31] | 2.88 [1.12 - 7.36] | 6.62 [2.35 - 18.64] | 19.78 [4.39 - 89.03] |
 The third-line treatment (platinum-based doublet vs. chemotherapy without platinum) | 1.26 [0.56 - 2.84] | 0.97 [0.38 - 2.46] | 0.35 [0.12 - 1.07] | 1.12 [0.31 - 4.07] |
 The third-line treatment (with pemetrexed vs. without pemetrexed) | 1.91 [0.69 - 5.27] | 2.34 [0.70 - 7.84] | 0.29 [0.07 - 1.26] | 0.14 [0.02 - 0.89] |