The impact of the lymph node density on overall survival in patients with Wilms’ tumor: a SEER analysis

Figures & data

Table 1 Patient characteristics in the study

Variable	Total	Low LND	High LND	P-value
Patients, n	1,924	1,641	283
Age (years), median (25th–75th percentile)	3 (2–5)	3 (2–5)	4 (3–6)	<0.001
Sex, n (%)				0.529
Male	917 (47.7)	787 (48.0)	130 (45.9)
Female	1,007 (52.3)	854 (52.0)	153 (54.0)
Race, n (%)				0.196
White	1,468 (76.3)	1,240 (75.6)	228 (80.6)
Black	329 (17.1)	287(17.5)	42 (14.8)
Other	105 (5.5)	94 (5.7)	11 (3.9)
LNs examined, median (25th–75th percentile)	4 (2–7)	4 (2–8)	3 (2–5)	<0.001
SEER stage, n (%)				<0.001
Localized	832 (43.2)	832 (50.7)	0 (0.0)
Regional	655 (34.0)	506 (30.8)	149 (52.7)
Distant	417 (21.7)	283 (17.2)	134 (47.3)
Surgery, n (%)				0.584
Yes	1,533 (79.7)	1,308 (79.7)	225 (79.5)
No	6 (0.3)	6 (0.4)	0 (0.0)
Unknown	385 (20.0)	327 (19.9)	58 (20.5)
Tumor laterality, n (%)				0.008
Unilateral	1,840 (95.6)	1,561 (95.1)	279 (98.6)
Bilateral	84 (4.4)	80 (4.9)	4 (1.4)
Year of diagnosis, n (%)				0.161
1988	24 (1.2)	22 (1.3)	2 (0.7)
1989–1997	359 (18.7)	303 (18.5)	56 (19.8)
1998–2000	166 (8.6)	133 (8.1)	33 (11.7)
2000–2014	1,375 (71.5)	1,183 (72.1)	192 (67.8)

Abbreviations: LNs, lymph nodes; LND, lymph node density; SEER, Surveillance, Epidemiology, and End Result.

Figure 1 Kaplan–Meier curve for overall survival stratified by the LND.

Abbreviations: LND, lymph node density.

Table 2 Univariate and multivariate Cox regression analysis using the LND as a categorical variable

Variable	Univariate analysis			Multivariate analysis
	HR	95% CI	P-value	HR	95% CI	P-value
Age	1.045	1.03–1.06	<0.001	1.049	1.032–1.065	<0.001
Sex
Male	Reference
Female	0.961	0.702–1.317	0.806
Race
White	Reference			Reference
Black	1.22	0.811–1.836	0.34	1.268	0.842–1.91	0.256
Other	1.802	1.015–3.202	0.044	1.992	1.103–3.595	0.022
LNs examined	0.984	0.954–1.015	0.303
SEER stage
Localized	Reference			Reference
Regional	1.701	1.115–2.593	0.014	1.467	0.939–2.29	0.092
Distant	3.839	2.578–5.717	<0.001	2.893	1.85–4.514	<0.001
Tumor laterality
Unilateral	Reference			Reference
Bilateral	1.988	1.127–3.51	0.018	2.014	1.111–3.653	0.021
Year of diagnosis
1988	Reference
1989–1997	2.836	0.387–20.778	0.305
1998–2000	3.798	0.503–28.656	0.196
2000–2014	3.156	0.434–22.957	0.256
LND stratification
Low LND	Reference			Reference
High LND	2.804	1.998–3.934	<0.001	2.102	1.44–3.07	<0.001

Abbreviations: HR, hazard ratio; LNs, lymph nodes; LND, lymph node density; SEER, Surveillance, Epidemiology, and End Result.

Table 3 Univariate and multivariate Cox regression analysis using the LND as a continuous variable

Variable	Univariate analysis			Multivariate analysis
	HR	95% CI	P-value	HR	95% CI	P-value
Age	1.045	1.03–1.06	<0.001	1.049	1.032–1.065	<0.001
Sex
Male	Reference
Female	0.961	0.702–1.317	0.806
Race
White	Reference			Reference
Black	1.22	0.811–1.836	0.34	1.242	0.825–1.869	0.299
Other	1.802	1.015–3.202	0.044	2.949	1.081–3.513	0.026
LNs examined	0.984	0.954–1.015	0.303
SEER stage
Localized	Reference			Reference
Regional	1.701	1.115–2.593	0.014	1.531	0.988–2.375	0.057
Distant	3.839	2.578–5.717	<0.001	2.965	1.907–4.612	<0.001
Tumor laterality
Unilateral	Reference			Reference
Bilateral	1.988	1.127–3.51	0.018	1.998	1.101–3.624	0.023
Year of diagnosis
1988	Reference
1989–1997	2.836	0.387–20.778	0.305
1998–2000	3.798	0.503–28.656	0.196
2000–2014	3.156	0.434–22.957	0.256
TLND	1.143	1.095–1.193	<0.001	1.098	1.046–1.152	<0.001

Abbreviations: HR, hazard ratio; LNs, lymph nodes; LND, lymph node density; SEER, Surveillance, Epidemiology, and End Result; TLND, ten times the LND.