Table 5.

Factors contributing to prognosis, as determined using univariate analysis

	No. patients	Medium survival rate (months)	2‐year survival rate (%)	5‐year survival rate (%)	P‐value for 5‐year survival rate
Gender
Male	45	23	43.7	11.0	0.074
Female	25	18	29.3	0.0
Tumor location
Head of pancreas/lesser pancreas	50	21	38.3	6.2	0.907
Body and tail of pancreas	20	21	40.0	10.0
Tumor size
Diameter ≥4.0 cm	40	21	33.6	3.1	0.459
Diameter <4.0 cm	30	23	45.1	15.2
Tumor differentiation
Low	22	16	24.1	0.0	0.030
High	48	23	45.1	11.7
Major vascular invasion
Yes	19	15	17.4	0	0.003
No	51	23	46.4	10.1
Lymphatic vessel invasion in adjacent tissue
Yes	41	19	22.2	0	<0.001
No	29	29	60.8	18.9
Lymph node metastasis
Positive	37	18	22.3	0	<0.001
Negative	33	28	56.3	14.6
PNP invasion
Positive	47	20	26.7	0	0.001
Negative	23	30	60.9	22.5

P‐values were calculated by the log‐rank test. PNP, peripancreatic nerve plexus.