Table 2 Univariate and Cox proportional hazards model of patient and clinicopathological factors influencing overall survival

Age

<50

–

–

≥ 50

1.19 (0.867–1.64)

1.30 (0.930–1.81)

0.125

Sex

Female

–

–

Male

1.35 (0.938–1.84

1.15 (0.825–1.61)

0.407

Symptom

Rectal bleeding

–

Change in bowel habit

1.31 (0.864–1.98)

Abdominal pain

1.30 (0.837–2.02)

Melena

1.28 (0.779–2.10)

Obstruction

1.14 (0.495–2.63)

Others

0.798 (0.291–2.19)

BMI

< 25

–

–

0.576^b

25–29.9

0.728 (0.503–1.05)

0.814 (0.555–1.20)

0.294

> 29.9

0.713 (0.472–1.08)

0.932 (0.603–1.44)

0.751

TNM stage

I

–

–

< 0.001^b

II

1.14 (0.590–2.20)

1.17 (0.603–2.28)

0.638

III

2.12 (1.12–4.03)

2.29 (1.19–4.38)

0.013

IV

6.14 (3.15–11.96)

6.06 (3.03–12.15)

< 0.001

Family history

Negative

–

Positive

0.947 (0.580–1.55)

–

–

Familial cancer

Non

–

–

CRC

1.05 (0.594–1.86)

Others

0.649 (0.240–1.76)

Tumor site

Colon

–

Rectum

1.03 (0.748–1.41)

Tumor grade

Well

–

–

0.097^b

Moderate

1.10 (0.790–1.54)

1.13 (0.796–1.61)

0.490

Poor

2.06 (1.30–3.25)

1.69 (1.05–2.71)

0.031

Smoker

No

–

Yes

1.68 (1.01–2.77)

1.00 (0.577–1.75)

0.991

Comorbidity

No

–

Yes

1.19 (0.812–1.73)

Imputed pre-operative CEA

< 5

–

–

≥ 5

1.34 (0.967–1.86)

1.41 (1.01–1.97)

0.046

Complete-case pre-operative CEA

< 5

–

≥ 5

1.52 (0.920–2.52)

1.26 (0.733–2.17)

0.403

Symptom duration

0.981 0.955–1.01)

0.984 (0.958–1.01)

0.223