Table 5: Univariate and multivariate analysis of overall survival.

CharacteristicsUnivariateMultivariate
HR95% CI valueHR95% CI value

Low-volume surgeon4511.0001.000
High-volume surgeon3210.4950.35–0.69<0.0010.7310.51–1.040.09

Age in years<0.001<0.001
 <50411.0001.000
 50–754941.0680.58–1.981.1100.82–1.77
 >752372.4261.30–4.521.5781.45–1.76

ASA-classification [16]<0.0010.01
 11581.0001.000
 24101.3840.92–2.081.3400.83–2.16
 31812.7261.78–4.171.9731.16–3.36
 4255.3983.07–9.493.1361.54–6.41

Comorbidity5231.5091.13–2.01<0.0011.0890.71–1.680.70
Cardiac1551.5691.17–2.11<0.0011.1900.79–1.790.40
Vascular2441.4271.10–1.86<0.0011.0840.78–1.520.64
Neurologic561.6631.09–2.540.021.1900.92–2.410.10
Urogenital661.7491.20–2.54<0.0011.2150.78–1.890.39

Open surgical technique 2581.0001.000
Laparoscopic5140.5220.41–0.67<0.0010.5950.43–0.83<0.001

No conversion 4001.0001.000
Conversion (laparoscopy only)1141.5101.10–2.080.011.4180.93–2.160.10

Blood loss intraoperatively7721.0011.00–1.01<0.0011.0001.00–1.000.63

Tumor stage<0.0010.67
 1501.0001.000
 21561.2350.57–2.661.5070.64–3.58
 34951.9990.98–2.661.4350.64–3.23
 4604.9562.30–10.71.9520.78–4.88

Nodal stage<0.001<0.001
 04451.0001.000
 12182.2621.68–3.041.9591.34–2.87
 21084.9973.61–6.923.0911.77–5.40
 3114.031.94–1015.6600.65–49.6

Metastatic stage<0.001<0.001
 06951.0001.000
 1775.0203.73–6.763.8831.34–2.87

Number of positive lymph nodes7721.1341.11–1.16<0.0011.0420.99–1.100.13

Resection margins<0.0010.08
 Complete resection (R0)7421.0001.000
 Microscopically irradical (R1)193.5202.05–6.052.2941.08–4.89
 Macroscopically irradical (R2)114.1532.12–8.121.7980.71–4.53

No adverse event6651.0001.000
Adverse event1071.9381.42–2.65<0.0011.1290.70–1.820.62

No adjuvant chemotherapy5541.0001.000
Adjuvant chemotherapy2181.5171.17–2.98<0.0011.1740.79–1.740.43

Only significant factors listed; 3 low-volume patients lost to follow-up; according to the AJCC TNM-staging system [17].