Table 2.

Prognostic factors after "extended" radical cholecystectomy for 52 patients with gallbladder cancer

Variable	n	Survival rate (%)		Univariate analysis	Multivariate analysis
		5-yr	10-yr	P value	Relative risk (95% CI)	P value
Age (yr)				0.002
≤ 65	20	80	80
> 65	32	50	35
pT classification1				< 0.001		0.001
pT1 plus pT2	39	82	70		1.000
pT3 plus pT4	13	15	0		5.947 (2.054-17.221)
pN classification1				0.037
pN0	29	79	67
pN1	12	58	33
pN2	11	36	36
pM classification1				< 0.001		0.002
pM0	48	71	57		1.000
pM1	4	0	0		20.068 (3.083-130.620)
Histological type1				< 0.001		0.001
Adenocarcinoma	48	71	57		1.000
Others	4	0	0		16.919 (3.015-94.939)
Histological grade1				0.021
G1	17	88	73
G2 plus G3 plus G4	35	54	43
Lymphatic vessel invasion (L)1				0.016
L0	20	85	73
L1	32	53	40
Venous invasion (V)1				0.004
V0	24	83	74
V1	28	50	34
Perineural invasion				0.041		0.084
Absent	36	72	62		1.000
Present	16	50	31		2.396 (0.889-6.460)
Residual tumor status1				< 0.001		0.071
R0	47	72	58		1.000
R1 plus R2	5	0	0		3.585 (0.897-14.329)

¹According to the American Joint Committee on Cancer Cancer Staging Manual (7th edition)[19]. CI: Confidence interval; pT classification: Pathological T classification; pN classification: Pathological regional lymph nodes classification; pM classification: Pathological distant metastasis classification; G1: Well differentiated; G2: Moderately differentiated; G3: Poorly differentiated; G4: Undifferentiated; L0: No lymphatic vessel invasion; L1: Lymphatic vessel invasion; V0: No venous invasion; V1: Microscopic venous invasion; R0: No residual tumor; R1: Microscopic residual tumor; R2: Macroscopic residual tumor.