Table 2 Univariate and multivariate analysis of prognostic factors for progression-free survival (PFS) and overall survival (OS) in advanced colorectal cancer

Univariate analysis

Gender

Male vs. Female

1.242

0.746

2.070

0.404

0.907

0.540

1.523

0.711

Age

<60 vs. ≥60

0.959

0.572

1.608

0.875

0.977

0.593

1.612

0.929

Tumor size

<5 vs. ≥5

1.173

0.708

1.944

0.535

0.766

0.465

1.259

0.293

Location

Colon vs. Rectum

0.945

0.564

1.584

0.831

1.331

0.809

2.190

0.261

Differentiation

Well vs. Middle vs. Poor

0.746

0.521

1.068

0.109

1.000

0.696

1.437

0.999

T

T1+T2 vs. T3 vs. T4a vs. T4b

1.164

.871

1.555

0.304

1.081

.810

1.442

0.597

N

N0 vs. N1 vs. N2a vs. N2b

1.255

1.009

1.562

0.042*

1.507

1.210

1.875

<0.001***

TNM

II+III vs. IVa vs. IVb

2.027

1.383

2.971

<0.001***

1.552

1.091

2.207

0.015*

CEA (ng/ml)

≤10 vs. >10

1.828

1.070

3.121

0.027*

1.452

0.884

2.385

0.141

CA199 (U/ml)

≤37 vs. >37

1.620

0.973

2.698

0.064

1.123

0.684

1.842

0.647

CTCs

Negative vs. Positive

2.870

1.716

4.801

<0.0001***

1.664

1.003

2.761

0.048*

Multivariate analysis

N

N0 vs. N1 vs. N2a vs. N2b

1.169

0.930

1.469

0.180

1.499

1.198

1.876

<0.001***

TNM

II + III vs. IVa vs. IVb

1.687

1.115

2.553

0.013*

1.580

1.086

2.298

0.017*

CEA (ng/ml)

≤10 vs. >10

1.258

0.712

2.224

0.429

CTCs

Negative vs. Positive

1.993

1.141

3.483

0.015*

1.148

0.679

1.943

0.606