Table 3. Five-year survival rates for 481 nasopharyngeal carcinoma patients with retropharyngeal lymph nodes metastasis according to the characteristics of retropharyngeal lymph node metastasis.

	Size (minimal axial diameters)			Necrosis			Laterality			Extranodal neoplastic spread
	<10 mm	≥10 mm	P *	No	Yes	P *	Unilateral	Bilateral	P *	No	Yes	P *
DMFS	86.5	71.9	<0.001	81.6	62.8	<0.001	82.5	73.6	0.032	81.6	70.3	0.001
DFS	78.3	62.9	<0.001	73.3	53.1	<0.001	73.6	65.5	0.054	74.1	58.1	0.002
LRRFS	93.5	87.3	0.017	92.0	80.0	<0.001	91.5	88.9	0.310	92.0	85.2	0.019

Abbreviations: DFS  =  disease-free survival; DMFS  =  Distant metastasis-free survival; LRRFS  =  Locoregional relapse-free survival.

*P values were calculated by the unadjusted log-rank test.