New development of biliary surgery in China

Table 1 Neural infiltration index and median survival time

Differentiation of tumor cells	PNI*	Median survival time (m)
Papillary	0.31 ± 0.12	32
High diff.	0.39 ± 0.18	13.5
Moderate diff.	0.74 ± 0.39	10.8
Low diff.	0.85 ± 0.41	7.2

*PNI ＞ 7.0 = severe nerve infiltration.

Table 2 Expression of NCAM and tumor differentiation

Cell type	NCAM expression
	(－)	(＋)
Papillary	5	3
High diff.	10	12
Moderate diff.	8	16
Low diff.	3	21

P = 0.0267, χ² = 9.20