Table 2 Prognostic factors for overall survival and recurrence-free survival

Age (year), (≤ 55 vs. > 55)

0.477

0.786

Gender (male vs. female)

0.785

0.479

 Left-sided vs. right-sided

0.575

0.029*

0.659

0.478–0.910

0.011*

 T stage (T3/T4 vs. T1/T2)

0.201

0.219

 N stage (N1/N2 vs. N0)

0.001*

1.600

1.155–2.216

0.005*

0.003*

1.533

1.159–2.029

0.003*

 Tumor size (cm), (> 4 vs. ≤ 4)

0.254

0.628

 Postoperative chemotherapy (yes vs. no)

0.501

0.018*

1.417

0.944–2.217

0.093

 Presentation of CRLM (synchronous vs. asynchronous)

0.766

0.190

 Preoperative chemotherapy (yes vs. no)

< 0.001*

1.279

0.898–1.822

0.172

0.001*

1.355

0.975–1.884

0.070

 CEA (μg/L), (> 200 vs. ≤ 200)

0.020*

1.166

0.560–2.428

0.681

0.056

 CA19-9 (kU/L), (> 35 vs. ≤ 35)

0.015*

1.285

0.854–1.933

0.229

0.748

 Tumor size (cm), (> 5 vs. ≤ 5)

0.001*

1.923

1.298–2.849

0.001*

0.315

 Tumor number (multiple vs. single)

< 0.001*

1.446

0.988–2.117

0.058

<0.001*

1.244

0.907–1.706

0.176

 Operative factors (with ablation vs. resection only)

< 0.001*

1.723

1.129–2.630

0.012

< 0.001*

1.793

1.253–2.566

0.001*

 R0 resection (no vs. yes)

< 0.001*

1.998

1.424–2.804

< 0.001*

 Postoperative chemotherapy (yes vs. no)

0.057

0.319