Table 5.

Cox proportional regression analysis for postoperative recurrence in 54 patients after excluding eight patients who underwent delayed surgery (n = 54)

	Univariate: HR (95% CI)	p-value	aMultivariate: HR (95% CI)	p-value
Age	1.028 (0.993,1.063)	0.117	AD.
Male	0.822 (0.406,1.666)	0.587	AD.
Tumor differentiation			AD.
Well
Moderate	1.090 (0.367,3.240)	0.877
Poor	1.374 (0.378,4.998)	0.629
Interval from initial imaging and operation (mo.)	0.934 (0.195,4.472)	0.932	AD.
Charlson co-morbidity index	1.043 (0.847,1.286)	0.691	0.784 (0.526,1.170)	0.233
Adjuvant chemotherapy	0.39 (0.185, 0.821)	0.013*	0.393 (0.137,1.128)	0.393
Preoperative CA19–9	1.09 (0.979,1.213)	0.115	1.127 (0.984,1.291)	0.085
Postoperative CA19–9	1.112 (1.018,1.214)	0.019*	1.148 (1.025,1.285)	0.017*
Radiologic tumor size	1.097 (0.664,1.812)	0.719	1.409 (0.768, 2.585)	0.268
Resectability
Resectable	1		1
Borderline resectable	1.683 (0.806,3.515)	0.166	2.123 (0.876,5.144)	0.096
Conspicuity score > 2	3.173 (1.522,6.613)	0.002*	3.944 (1.739, 8.945)	0.001*
Pathologic tumor size (cm)	1.586 (1.026,2.452)	0.038*	2.064 (1.265, 3.366)	0.004*
Positive resection margin	1.32 (0.499,3.490)	0.575	1.147 (0.384, 3.427)	0.806
Lymphatic invasion	2.299 (1.048,5.045)	0.038*	2.966 (1.153,7.629)	0.024*
Perineural invasion	2.014 (0.818,4.958)	0.128	3.569 (1.194,10.67)	0.023*
Microvascular invasion	1.135 (0.454, 2.835)	0.787	1.545 (0.531,4.498)	0.425
Pathologic T stage
T1	1		1
T2	0.383 (0.079,1.846)	0.232	0.536 (0.062,5.124)	0.610
T3	0.600 (0.135,2.663)	0.502	0.918 (0.108,7.816)	0.937
Positive lymph node	1.157 (0.559, 2.392)	0.695	1.117 (0.47,2.653)	0.802

^a Adjusted for age, sex, concomitant pancreatitis, tumor location, tumor differentiation, and interval between initial imaging and operation

HR hazard ratio, CI confidence interval

* p-value less than 0.05