Table 2 Univariate analysis for progression-free survival

Age, years

1.27 (0.78–2.09)

0.327

2.19 (0.97–5.94)

0.076

 < 61

13.0 (11.3–16.0)

 ≥ 61

12.0 (10.0–14.4)

Gender

0.93 (0.58–1.37)

0.481

0.81 (0.63–1.98)

0.656

 Female

12.0 (10.0–16.0)

 Male

12.9 (11.1–15.1)

ECOG PS

1.65 (0.88–3.13)

0.119

1.74 (0.67–5.27)

0.336

 0–1

13.0 (11.5–14.8)

 ≥ 2

10.7 (7.9–16.1)

Tumor location

0.87 (0.66–1.19)

0.351

0.79 (0.59–1.21)

0.195

 Right lung

12.9 (10.4–15.1)

 Left lung

12.0 (8.8–23.5)

 Right + left

13.0 (9.5–16.6)

Tumor size at baseline (cm)

1.07 (0.76–1.50)

0.685

1.05 (0.64–1.67)

0.855

 ≤ 3

13.0 (8.8–15.6)

 > 3–5

13.7 (11.3–19.3)

 > 5 

12.6 (9.8–14.4)

M-Staging

1.06 (0.75–1.50)

0.723

0.97 (0.58–1.59)

0.662

 M0

9.7 (6.0–28.3)

 M1a

13.0 (8.8–19.7)

 M1b

12.6 (11.3–14.5)

Brain metastasis at baseline

0.89 (0.56–1.53)

0.669

0.76 (0.45–1.72)

0.392

 No

12.9 (10.4–14.8)

 Yes

12.6 (11.1–15.2)

Bone metastasis at baseline

1.27 (0.78–2.08)

0.342

1.07 (0.62–2.65)

0.891

 No

13.0 (10.0–17.5)

 Yes

12.3 (11.1–15.1)

Liver metastasis at baseline

1.20 (0.77–2.15)

0.539

1.88 (0.81–5.72)

0.269

 No

12.9 (10.0–14.2)

 Yes

11.5 (9.0–15.1)

Pleural effusion at baseline

0.97 (0.57–1.64)

0.791

1.17 (0.67–2.86)

0.737

 No

12.9 (11.1–14.8)

 Yes

12.6 (10.0–19.3)

EGFR mutation type

1.45 (0.88–2.39)

0.139

1.84 (0.72–4.72)

0.204

 E19del

13.7 (11.3–16.0)

 L858R

12.0 (9.5–13.8)

EGFR plasma at baseline

1.43 (0.77–3.61)

0.346

1.22 (0.69–3.01)

0.672

 Negative

12.0 (5.3-NR)

 Positive

9.7 (7.1–14.1)

 Unknown

13.0 (11.3–15.1)

Treatment method

1.35 (0.99–1.83)

0.051

1.40 (0.81–2.44)

0.237

 TKI alone

12.1 (9.8–14.2)

 TKI + Che/Ra

11.1 (9.0–13.0)

 TKI + Sur

14.8 (11.5–18.2)

Brain metastasis after treatment

2.38 (1.30–4.38)

0.005

1.26 (0.89–3.42)

0.316

 No

13.0 (11.5–15.6)

 Yes

8.3 (7.7–11.3)

Bone metastasis after treatment

1.33 (0.80–2.19)

0.273

1.43 (0.66–3.62)

0.450

 No

13.0 (11.1–15.6)

 Yes

11.5 (9.7–16.0)

Liver metastasis after treatment

1.65 (0.96–2.86)

0.078

2.19 (0.98–5.46)

0.082

 No

13.0 (10.4–16.0)

 Yes

12.0 (8.8–13.7)

Pleural effusion after treatment

1.35 (0.81–2.23)

0.249

1.55 (0.68–4.10)

0.379

 No

13.0 (11.5–15.1)

 Yes

11.1 (9.8–15.6)

New metastasis site

2.51 (1.52–4.11)

< 0.001

3.35 (1.27–8.82)

0.014

 No

14.5 (13.0–18.2)

 Yes

9.0 (8.3–12.1)

EGFR plasma after treatment

3.58 (1.77–7.25)

< 0.001

6.13 (1.79–21.01)

0.003

 Negative

NR (13.7-NR)

 Positive

11.1 (9.5–12.9)

Secondary T790M

1.94 (1.19–3.17)

0.008

3.01 (1.22–7.41)

0.017

 Negative

13.8 (12.6–17.5)

 Positive

10.0 (8.8–12.1)

cfDNA (ng/mL)

1.47 (0.88–2.46)

0.144

1.82 (0.80–4.74)

0.217

 ≤ 200 

12.9 (11.0–19.5)

 > 200 

12.2 (10.7–13.8)