Table 5 Univariate and multivariate Cox regression analyses of overall survival in 372 elderly patients after curative resection

Gender: male/female

1.51 (1.06–2.17)

0.024

1.31 (0.91–1.90)

0.151

Age at operation: ≥ 85/ < 85

1.65 (0.77–3.54)

0.199

0.56 (0.37–0.85)

0.107

ASA score: III/II

0.37 (0.25–0.54)

0.225

Body mass index: ≥ 24/ < 24

1.99 (1.22–3.25)

0.006

1.45 (0.87–2.40)

0.005

Preoperative albumin: ≥ 35/ < 35

1.15 (0.80–1.66)

0.442

Preoperative HGB: ≥ 110/ < 110

1.34 (0.83–2.16)

0.236

Habits: drinking

0.93 (0.58–1.48)

0.754

Habits: smoking

0.93 (0.58–1.48)

0.753

Comorbity: yes/no

1.51 (1.03–2.20)

0.035

1.34 (0.90–1.99)

0.144

Previous abdominal surgery:yes/no

1.16 (0.76–1.79)

0.488

Tumor location

 Left colon

Reference

-

 Right colon

0.94 (0.58–1.53)

0.805

 Rectum

1.00 (0.66–1.52)

0.997

Surgical procedure: open/laparoscope

0.24 (0.16–0.35)

0.223

0.34 (0.23–0.53)

0.121

Operative time: ≥ 135/ < 135

1.07 (0.72–1.59)

0.734

T stage: T3-T4/T1-T2

0.87 (0.57–1.32)

0.505

N stage: N1-N2/N0

2.56 (1.72–3.80)

 < 0.001

2.14 (1.40–3.26)

 < 0.001

Tumor grade

 I

Reference

-

 II

2.48 (1.15–5.36)

0.021

1.66 (0.75–3.70)

0.215

 III

3.34 (1.45–7.69)

0.005

1.71 (0.71–4.10)

0.230

Perineural invasion: yes/no

0.97 (0.67–1.39)

0.850

Lymphatic invasion

0.95 (0.63–1.43)

0.812

Grade 3–4 complications: yes/no

0.58 (0.36–0.92)

0.021

0.78 (0.48–1.27)

0.345

Re-operation: yes/no

1.59 (0.51–5.02)

0.427