Prognostic impact of number of examined lymph nodes on survival of patients with appendiceal neuroendocrine tumors

Table 2 Univariate analysis using Cox proportional hazard model

Factor	Category	HR	95%CI	Log-rank P value
Age	≤ 40 yr	-	-	P < 0.001
	41-65 yr	7.25	5.09-10.32
	≥ 66 yr	16.14	11.08-23.52
Year	1975-1980	-	-	P < 0.001
	1981-1990	3.06	1.56-6.01
	1991-2000	4.72	2.51-8.85
	2001-2010	3.83	2.09-7.02
	2011-2016	1.84	0.98-3.43
Race	White	-	-	P = 0.02
	Other	1.15	0.73-1.83
	Black	1.58	1.20-2.08
Sex	Male	-	-	P = 0.80
	Female	1.02	0.85-1.23
Grade	Grade 1/2	-	-	P < 0.001
	Grade 3/4	19.14	13.63-26.87
Histological type	Carcinoid tumor	-	-	P < 0.001
	Neuroendocrine carcinoma	2.36	1.44-3.88
	Goblet cell carcinoid	4.98	3.61-6.87
	Adenocarcinoid tumor	6.87	4.89-9.64
	Mixed adenoneuroendocrine carcinoma	14.45	10.30-20.27
Tumor size	≤ 2 cm	-	-	P < 0.001
	> 2 cm	8.54	5.99-12.17
Stage	I/II	-	-	P < 0.001
	III/IV	17.12	11.78-24.87
T stage	T1	-	-	P < 0.001
	T2	5.16	1.29-20.64
	T3	17.25	6.09-48.81
	T4	117.44	43.03-320.55
M stage	M0	-	-	P < 0.001
	M1	31.37	22.16-44.39
N stage	N0	-	-	P < 0.001
	N1	8.44	6.69-10.65
Surgery	Local resection	-	-	P < 0.001
	Colectomy or greater	3.47	1.95-6.17
ELNs	≥ 11	-	-	P < 0.001
	≤ 10	1.75	1.37-2.23
LNR	0-0.16	-	-	P < 0.001
	0.17-0.48	3.23	2.25-4.64
	0.49-1	7.70	5.38-11.01

ELNs: Examined lymph nodes; LNR: Lymph node ratio (the ratio of positive lymph nodes to the total lymph nodes examined).