Table 2 Univariate analyses of potential prognostic factors for OS using the training cohort

Age(year)

  < 65

1

  ≥ 65

1.010(0.841–1.213)

Gender

 Male

1

 Female

1.038(0.868–1.242)

Smoking

 Smoker

1

 Never-smoker

0.811(0.669–0.984)

PS

 0–1

1

  ≥ 2

1.169(0.980–1.395)

Synchronous BM

 Yes

1

 No

0.919(0.752–1.123)

Maximum diameter of BM lesions

  < 2 cm

1

  ≥ 2 cm

1.235(1.046–1.459)

Receiving local treatment (Surgery/WBRT/SRS)

 Yes

1

 No

2.199(1.852–2.610)

Receiving chemotherapy

 yes

1

 no

1.897(1.573–2.289)

NLR

  ≥ 4.71

1

  < 4.71

0.568(0.468–0.689)

Albumin

  < 40 mg/l

1

  ≥ 40 mg/l

0.523(0.438–0.625)