Table 1. Baseline demographic and tumor characteristics of patients with cervical cancer in SEER database.

Parameter	Characteristic	N	NLN = 0~6	NLN = 7~	χ2	P value
Year of diagnosis					9.597	0.002
	2004–2008	6656	672	5984
	2009–2012	3844	463	3381
Age					60.255	0.000
	<60	9236	918	8318
	≥60	1264	217	1047
Race					56.815	0.000
	White	8389	829	7560
	Black	956	170	786
	Others	1155	136	1019
Grade					20.861	0.000
	I/II	4955	466	4489
	III/IV	3394	395	2999
	Unknown	2151	274	1877
Primary Site					0.649	0.885
	Endocervix	2377	256	2121
	Exocervix	338	33	305
	Overlapping lesion	343	40	303
	Cervix uteri	7442	806	6636
Histologic type					9.019	0.011
	Squamous cell carcinoma	7377	841	6536
	Adenocarcinoma	2901	274	2627
	Mucinous adenocarcinoma	222	20	202
FIGO stage					256.214	0.000
	I	7343	644	6699
	II	1003	184	819
	III	261	89	172
	IV	32	11	21
	Unknown	1861	207	1654
Radiation					168.765	0.000
	No radiation	7299	590	6639
	Radiation after surgery	3271	545	2726