Table 4 Time to Treatment Failure and Related Factors

Age

•       < 65 years old

15.7

0.712

1.00 (reference)

-

-

•       ≥ 65 years old

17.5

0.95 (0.72–1.25)

Gender

•       Male

15.7

0.056

1.00 (reference)

-

-

•       Female

19

0.76 (0.58–1.01)

ECOG

•       PS 0–1

16.9

0.878

1.00 (reference)

•       PS 2–3

15.7

0.96 (0.57–1.63)

Smoking status

•       Current smoker

17.5

0.243

1.00 (reference)

-

-

•       Non/former smoker

15.4

0.83 (0.61–1.13)

EGFR mutations

•       Del 19

17

0.225^a

-

-

-

•       L858R

19.6

-

-

-

•       Common mutation

17.5

0.045^b

1.00 (reference)

0.007^b

1.00 (reference)

•       Uncommon mutations

13.8

1.36 (1.01–1.83)^b

1.53 (1.13–2.07)^b

Stage

•       IV

16.7

0.666

1.00 (reference)

-

-

•       IIIB, IIIC, recurrence

17.5

0.90 (0.55–1.47)

Brain metastasis

•       No

17.5

0.042

1.00 (reference)

0.026

1.00 (reference)

•       Yes

15.1

1.37 (1.01–1.85)

1.42 (1.04–1.92)

Liver metastasis

•       No

17

0.2

1.00 (reference)

-

-

•       Yes

12.5

1.32 (0.86–2.03)

Starting dose

•       40 mg

16.7

0.755

1.00 (reference)

-

-

•       < 40 mg

16.9

1.05 (0.79–1.38)

Optimal dose

•       40 mg

15.2

0.003

1.00 (reference)

0.041

1.00 (reference)

•       < 40 mg

18.5

0.65 (0.48–0.87)

0.72 (0.53–0.99)

Dose reduction

•       No

15.7

< 0.001

1.00 (reference)

0.003

1.00 (reference)

•       Yes

22

0.54 (0.39–0.76)

0.58 (0.41–0.83)