Table 4 Univariate and multivariate cancer-specific survival analyses for the influence of tumor size in perihilar cholangiocarcinoma

Age

< 60

Reference

0.060

≥60

1.354 (0.988–1.858)

Race

White

Reference

0.125

Black

1.165 (0.684–1.984)

Others

1.419 (1.011–1.991)

Sex

Female

Reference

Male

0.939 (0.708–1.247)

0.666

Grade

Well/moderate

Reference

< 0.001

Reference

0.003

Poor/undifferentiated

1.899 (1.401–2.574)

1.733 (1.262–2.379)

Unknown

1.255 (0.31–1.897)

1.335 (0.860–2.073)

T stage

T1

Reference

0.007

Reference

0.170

T2

1.634 (1.043–2.558)

1.209 (0.756–1.932)

T3

1.997 (1.164–3.426)

1.063 (0.599–1.886)

T4

2.655 (1.424–4.951)

1.411 (0.735–2.711)

Tx

2.324 (1.3753.929)

1.801 (1.032–3.143)

M stage

M0

Reference

0.063

M1

1.676 (0.973–2.887)

RN status

RN examined and not positive

Reference

< 0.001

Reference

< 0.001

RN examined and < 4 nodes positive

2.294 (1.658–3.175)

2.168 (1.551–3.031)

RN examined and > =4 nodes positive

2.968 (1.857–4.743)

2.592 (1.562–4.302)

RN not examined or RN unknown

2.026 (1.317–3.119)

1.952 (1.254–3.039)

Vascular Invasion

Absent

Reference

0.062

Present

1.432 (0.981–2.090)

Tumor size

1–19 mm

Reference

< 0.001

Reference

0.008

20-33 mm

1.525 (1.034–2.249)

1.264 (0.844–1.894)

≥34 mm

2.354 (1.586–3.494)

1.834 (1.209–2.780)