Table 4 Risk factors for lymph node metastasis and liver metastasis identified by univariate logistic regression analysis

Age

 <45

1

1

 45–65

0.86

0.729–1.016

0.76

0.774

0.5–1.2

 ≥ 65

0.609

0.517–0.717

0.528

0.342–0.814

Gender

 Female

1

1

 Male

1.02

0.946–1.101

0.606

1.222

0.98–1.524

Marital status

 Married

1

1

 Single

0.917

0.847–0.993

0.033

1.194

0.951–1.499

 Unknown

0.758

0.638–0.901

0.002

1.065

0.667–1.7

Race

 Asian or Pacific Islander

1

1

 American Indian/Alaska Native

0.792

0.495–1.265

0.328

1.344

0.306–5.899

 White

0.735

0.642–0.841

1.469

0.884–2.442

 Black

1.015

0.863–1.193

0.858

2.278

1.305–3.976

Histological grade

 Well differentiated

1

1

 Moderately differentiated

1.667

1.493–1.883

< 0.001

1.891

1.318–2.713

 Poorly differentiated

3.739

3.217–4.345

< 0.001

2.891

1.829–4.571

 Undifferentiated

3.617

2.763–4.735

< 0.001

3.043

1.396–6.626

Histological type

 Adenocarcinoma

1

1

 Carcinoid tumor

0.862

0.679–1.094

0.222

0.306

0.098–0.957

 Neuroendocrine carcinoma

2.14

1.547–2.96

< 0.001

1.376

0.508–3.371

 Mucinous adenocarcinoma

1.231

1.043–1.453

0.014

1.303

0.833–2.308

 Other

1.124

0.946–1.336

0.183

0.629

0.334–1.185

T classification

 T1

1

1

 T2

2.461

2.271–2.665

< 0.001

1.789

1.426–2.244

Tumor size

 <5 cm

1

1

 ≥ 5 cm

1.494

1.34–1.666

< 0.001

4.212

3.269–5.425

 Unknown

0.58

0.509–0.66

< 0.001

1.894

1.406–2.553

CEA

 Negative

1

1

 Borderline

1.338

0.688–2.601

0.391

2.815

0.382–20.726

 Positive

1.477

1.316–1.658

< 0.001

12.309

9.035–16.77

 Unknown

0.669

0.616–0.727

1.249

0.893–1.746

Tumor number

 1

1

1

 2

0.915

0.834–1.004

0.061

1.222

0.947–1.573

 3

0.863

0.727–1.024

0.091

1.134

0.714–1.8

 >3

0.933

0.703–1.238

0.631

0.859

0.352–2.096

N classification

 N0

1

1

 N1

NA

NA

NA

4.687

3.64–6.036

 N2

NA

NA

NA

17.35

12.761–23.59