Table 4.

Cox proportional regression analysis for postoperative recurrence (n = 62)

	Univariate: HR (95% CI)	p-value	aMultivariate: HR (95% CI)	p-value
Age	1.019 (0.989,1.050)	0.210	AD.
Male	0.893 (0.474,1.684)	0.727	AD.
Tumor differentiation			AD.
Well
Moderate	1.031 (0.419,2.535)	0.948
Poor	1.187 (0.393,3.581)	0.761
Interval between initial imaging and operation (mo.)	1.085 (0.990,1.189)	0.08	AD.
CCI	1.044 (0.865,1.260)	0.653	0.918 (0.675–1.248)	0.585
Adjuvant chemotherapy	0.474 (0.242,0.926)	0.029*	0.544 (0.220–1.343)	0.187
Preoperative CA19–9	1.105 (1.007,1.214)	0.036*	1.146 (1.022–1.286)	0.02*
Postoperative CA19–9	1.105 (1.021,1.196)	0.014*	1.114 (1.006–1.232)	0.037*
Radiologic tumor size	1.248 (0.882,1.767)	0.211	1.483 (0.966–2.276)	0.072
Resectability
Resectable	1		1
Borderline resectable	1.560 (0.799,3.049)	0.193	1.868 (0.833–4.188)	0.129
Unresectable	4.018 (0.896,18.012)	0.069	1.349 (0.093–19.548)	0.826
Conspicuity score > 2	3.122 (1.616,6.029)	0.001*	3.669 (1.735,7.762)	0.001*
Pathologic tumor size (cm)	1.383 (1.058, 1.807)	0.018*	1.612 (1.062–2.448)	0.025*
Positive resection margin	1.528 (0.664,3.514)	0.318	1.407 (0.552–3.583)	0.475
Lymphatic invasion	2.058 (1.043,4.059)	0.037*	2.757 (1.224–6.211)	0.014*
Perineural invasion	1.659 (0.815,3.378)	0.163	2.448 (1.048–5.721)	0.039
Microvascular invasion	1.318 (0.61,2.848)	0.482	1.464 (0.644–3.327)	0.363
Pathologic T stage
T1	1		1
T2	0.417 (0.089,1.947)	0.266	0.583 (0.069–4.928)	0.620
T3	0.588 (0.135,2.588)	0.480	0.739 (0.09–6.055)	0.778
T4	0.402 (0.035,4.645)	0.465	0.535 (0.022–13.170)	0.702
Positive lymph node	1.178 (0.615, 2.256)	0.622	1.261 (0.605–2.630)	0.536

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

HR hazard ratio, CI confidence interval, CCI Charlson co-morbidity index

* p-value less than 0.05