Table 3 Cox proportional hazards model evaluating the effect of clinical variables on overall survival

Age (every one year)

1.01

1.00–1.02

0.028^*

1.01

0.99–1.02

0.121

Sex (male vs. female)

1.31

1.05–1.64

0.019^*

1.29

1.02–1.64

0.034^*

ECOG PS

 0

Ref

Ref

 1

2.08

1.57–2.75

 < 0.001^*

1.80

1.33–2.42

 < 0.001^*

  ≥ 2

3.79

2.69–5.34

 < 0.001^*

2.82

1.94–4.10

 < 0.001^*

Group

 TC-/PPI-

Ref

Ref

 TC + /PPI-

0.65

0.45–0.93

0.019^*

1.07

0.73–1.59

0.708

 TC-/PPI + 

1.70

1.31–2.20

 < 0.001^*

1.50

1.15–1.96

0.003^*

 TC + /PPI + 

0.99

0.70–1.39

0.931

1.30

0.89–1.88

0.175

Brain metastases

2.24

1.75–2.86

 < 0.001^*

2.11

1.62–2.73

 < 0.001^*

Skin rash

0.25

0.19–0.32

 < 0.001*

0.28

0.21–0.37

 < 0.001^*