Impact of the number of examined lymph nodes on outcomes in patients with lymph node-negative gallbladder carcinoma

Table 1 Demographic and tumor characteristics for patients with lymph node-negative gallbladder carcinoma n (%)

Characteristics	Entire cohortn = 893 (100%)	Stage I1n = 228 (25.5%)	Stage II1n = 444 (49.7%)	Stage IIIA1n = 221 (24.7%)	P2Value
Age, yr
Median (range)	67 (21-96)	67 (21-92)	67 (25-96)	67 (35-93)	0.575
Sex
Male	272 (30.5)	63 (27.6)	139 (31.3)	70 (31.7)
Female	621 (69.5)	165 (72.4)	305 (68.7)	151 (68.3)	0.559
Race
White	675 (75.6)	162 (71.1)	34.1 (76.8)	172 (77.8)
Black	106 (11.9)	33 (14.5)	50 (11.3)	23 (10.4)
Others	112 (12.5)	33 (14.5)	53 (11.9)	26 (11.8)	0.261
Grade1
Well	187 (20.9)	67 (29.4)	102 (23.0)	18 (8.1)
Moderate	414 (46.4)	101 (44.3)	215 (48.4)	98 (44.3)
Poor	210 (23.5)	26 (11.4)	96 (21.6)	88 (39.8)
Undifferentiated	11 (1.2)	1 (0.4)	5 (1.1)	5 (2.3)
Unknown	71 (8.0)	33 (14.5)	26 (5.9)	12 (5.4)	< 0.001
Radiation
Yes	151 (16.9)	8 (3.5)	75 (16.9)	68 (30.8)
No	742 (83.1)	220 (96.5)	369 (83.1)	153 (69.2)	< 0.001
Vital status
Alive	547 (61.3)	151 (66.2)	308 (69.4)	88 (39.8)
Dead	346 (38.7)	77 (33.8)	136 (30.6)	133 (60.2)	< 0.001
Number of LN
Median (range)	2 (1-80)	1 (1-80)	2 (1-40)	2 (1-24)	0.590

¹AJCC/TNM 8^th edition.

²Factors were compared by the independent t test and the χ² test for continuous and categorical variables, respectively. LN: Lymph node.

Table 2 Survival by lymph node group and stage

Number of LN	Entire cohort n = 893 (100%)	Stage I1n = 228 (25.5%)	Stage II1n = 444 (49.7%)	Stage IIIA1n = 221 (24.7%)
1 LN
Patients (n)	398	121	189	88
Median OS, mo	18	24	20	10
3-yr SR (95%CI)	0.503 (0.474-0.532)	0.603 (0.553-0.653)	0.608 (0.566-0.650)	0.271 (0.217-0.325)
5-yr SR (95%CI)	0.393 (0.361-0.425)	0.473 (0.418-0.528)	0.445 (0.394-0.496)	0.177 (0.128-0.226)
2 LNs
Patients (n)	129	35	68	26
Median OS, mo	28	43	27	15
3-yr SR (95%CI)	0.711 (0.665-0.757)	0.808 (0.737-0.879)	0.775 (0.713-0.837)	0.425 (0.317-0.533)
5-yr SR (95%CI)	0.579 (0.524-0.634)	0.725 (0.640-0.810)	0.586 (0.504-0.668)	0.340 (0.225-0.455)
3 LNs
Patients (n)	85	20	33	32
Median OS, mo	21	30	27	11
3-yr SR (95%CI)	0.587 (0.525-0.649)	0.722 (0.603-0.841)	0.697 (0.606-0.788)	0.379 (0.277-0.481)
5-yr SR (95%CI)	0.466 (0.396-0.536)	0.602 (0.454-0.750)	0.639 (0.539-0.739)	0.203 (0.109-0.297)
4 LNs
Patients (n)	55	8	31	16
Median OS, mo	22	22	27	10
3-yr SR (95%CI)	0.638 (0.560-0.716)	0.833 (0.681-0.985)	0.760 (0.671-0.849)	0.295 (0.154-0.446)
5-yr SR (95%CI)	0.533 (0.438-0.628)	0.833 (0.681-0.985)	0.652 (0.526-0.778)	0.148 (0.022-0.274)
5 LNs
Patients (n)	43	10	21	12
Median OS, mo	24	38	24	18
3-yr SR (95%CI)	0.750 (0.671-0.829)	0.857 (0.725-0.989)	NA	0.292 (0.133-0.451)
5-yr SR (95%CI)	0.652 (0.557-0.747)	0.714 (0.543-0.885)	0.857 (0.725-0.989)	0.146 (0.016-0.276)
≥ 6 LNs
Patients (n)	183	34	102	47
Median OS, mo	26	26	26	21
3-yr SR (95%CI)	0.696 (0.655-0.737)	0.817 (0.731-0.903)	0.753 (0.701-0.805)	0.498 (0.412-0.584)
5-yr SR (95%CI)	0.594 (0.547-0.641)	0.817 (0.731-0.903)	0.671 (0.610-0.732)	0.306 (0.221-0.391)

¹AJCC/TNM 8^th edition. LN: Lymph node; OS: Overall survival; SR: Survival rate; NA: Not available.

Table 3 Multivariate analyses for overall survival in patients with lymph node-negative gallbladder carcinoma

Variable	Entire cohortn = 893 (100%)		Stage I1n = 228 (25.5%)		Stage II1n = 444 (49.7%)		Stage IIIA1n = 221 (24.7%)
	HR (95%CI)	aP	HR (95%CI)	bP	HR (95%CI)	cP	HR (95%CI)	dP
Age, yr	1.001 (1.000-1.002)	0.504	1.001 (1.000-1.002)	0.934	1.001 (1.000-1.002)	0.449	1.001 (1.000-1.002)	0.057
Sex
Male	1		1		1		1
Female	0.684 (0.532-0.879)	0.003	0.317 (0.156-0.645)	0.002	0.553 (0.346-0.881)	0.013	0.494 (0.299-0.818)	0.006
Race
White	1		1		1		1
Black	1.475 (1.008-2.160)	0.046	4.593 (1.625-12.981)	0.004	1.645 (0.775-3.490)	0.195	2.245 (0.904-5.575)	0.082
Others	0.821 (0.551-1.224)	0.334	0.262 (1.975)	0.719	0.509 (0.245-1.056)	0.070	1.362 (0.609-3.047)	0.452
Grade1
Well	1		1		1		1
Moderate	0.840 (0.609-1.157)	0.286	0.418 (0.194-0.902)	0.026	1.568 (0.905-2.715)	0.109	0.297 (0.125-0.704)	0.006
Poor	1.291 (0.908-1.835)	0.155	1.339 (0.449-3.994)	0.601	2.412 (1.306-4.453)	0.005	0.629 (0.259-1.531)	0.307
Undifferentiated	2.101 (0.891-4.954)	0.090	/	/	4.059 (1.033-15.951)	0.045	1.434 (0.323-6.373)	0.636
Unknown	0.856 (0.503-1.455)	0.565	0.384 (0.134-1.106)	0.076	2.376 (0.857-6.583)	0.096	0.260 (0.068-1.003)	0.050
Radiation
No	1		1		1		1
Yes	0.727 (0.515-1.027)	0.071	1.055 (0.302-3.688)	0.933	0.781 (0.430-1.419)	0.417	0.390 (0.215-0.708)	0.002
No. of LNs examined	1.001 (1.000-1.002)	0.162	1.001 (1.000-1.002)	0.910	1.001 (1.000-1.002)	0.382	1.001 (1.000-1.002)	0.167
Stage1
I	1		/	/	/	/	/	/
II	1.089 (0.793-1.497)	0.598	/	/	/	/	/	/
IIIA	3.730 (2.635-5.280)	0.000	/	/	/	/	/	/

¹AJCC/TNM 8^th edition. OS: Overall survival.