Table 3.

Cox proportional hazard analysis of prognostic factors for overall survival

Parameter	HR	95%LCL	95%UCL	P value
Patients’ demographics and tumor characteristics
CEA (ng/mL), IQR 1.70–4.95	1.00	0.92	1.09	0.945
CA19-9 (U/mL), IQR 37.55–333.45	1.34	0.98	1.84	0.067
Tumor location				0.003*
Head	1
Body	0.05	0.01	0.37
Tail	0.17	0.04	0.7
Tumor size (mm)	1.78	0.93	3.42	0.081
pT stage				0.221
0	1
1c	16.82	0	1.27e + 46
2	83.65	0	6.21e + 46
3	206.67	0	1.55e + 47
pN stage				0.038*
0	1
1	2.23	0.59	8.48
2	5.4	1.46	20.0
TNM stage		0.088
1A	1
1B	1.69	0.17	16.4
2B	3.21	0.37	27.94
3	7.74	0.92	65.02
Tumor differentiation				0.775
Poor	1
Moderate	1.89	0.23	15.5
Well	1.34	0.11	16.24
R classification	4.14	1.42	12.07	0.009*
Histogram analysis parameters
Mean, IQR 1320.57–1740.09	0.64	0.32	1.29	0.212
Standard error, IQR 17.84–36.08	0.63	0.32	1.24	0.183
Median, IQR 1318.04–1720.21	0.64	0.62	1.27	0.198
Mode, IQR 1237.17–1586.52	0.88	0.53	1.47	0.629
Standard deviation, IQR 96.20–192.00	1.02	0.56	1.86	0.941
Variance, IQR 9268.55–36,867.38	0.93	0.58	1.51	0.771
Kurtosis, IQR 2.20–3.06	7.11	2.42	20.9	< 0.001*
Skewness, IQR -0.50–0.35	0.92	0.37	2.31	0.86
CV, IQR 0.06–0.13	1.25	0.67	2.33	0.479
Minimum, IQR 1070.98–1412.84	0.62	0.35	1.11	0.107
Maximum, IQR 1626.85–2044.53	0.83	0.5	1.4	0.49
Entropy, IQR 1.29–1.56	2.06	1.16	3.66	0.013*
Energy, IQR 0.03–0.05	0.49	0.25	0.97	0.04*

HR for continuous variable represents the risk of the 75th percentile relative to the 25th percentile. HR for categorical variable is set to 1 for the reference category

e + 46 means 10 to the 46th power. e + 47 means 10 to the 47th power

HR, hazard ratio; LCL, lower confidence limit; UCL, upper confidence limit; IQR, interquartile range (25th-75th percentile); CV, coefficient of variance

*P < 0.05, significant difference