Patterns and Prognostic Value of Lymph Node Metastasis on Distant Metastasis and Survival in Nasopharyngeal Carcinoma: A Surveillance, Epidemiology, and End Results Study, 2006–2015

Table 2

Kaplan–Meier analyses for 5-year OS and CSS rates and multivariate analyses using Cox proportional hazards regression model in all 2994 NPC patients.

Characteristics	5-year OS		Cox proportional HR		5-year CSS		Cox proportional HR
	Rate (%)		HR (95% CI)		Rate (%)		HR (95% CI)
Age group (years)
<40	76.6	<0.001	1		78.5	<0.001	1
40–49	67.5		1.394 (1.072, 1.812)	0.013	68.8		1.392 (1.057, 1.834)	0.019
50–59	59.9		1.858 (1.455, 2.373)	<0.001	63.8		1.768 (1.366, 2.290)	<0.001
60–69	49.8		2.422 (1.880, 3.120)	<0.001	54.4		2.189 (1.672, 2.866)	<0.001
>70	36.1		3.812 (2.939, 4.945)	<0.001	47.4		3.036 (2.289, 4.028)	<0.001
Sex
Male	57.6	0.002	1		61.7	0.002	1
Female	64.1		0.851 (0.738, 0.980)	0.026	68.9		0.843 (0.721, 0.986)	0.032
Race^a
Asian/Pacific Islander	67.3	<0.001	1		70.2	<0.001	1
White	55.0		1.476 (1.272, 1.712)	<0.001	60.2		1.410 (1.201, 1.657)	<0.001
Black	51.8		1.610 (1.315, 1.971)	<0.001	57.7		1.505 (1.209, 1.874)	<0.001
American Indian/Alaska Native	43.8		1.717 (1.117, 2.638)	0.014	45.3		1.719 (1.095, 2.698)	0.018
Histology
KSCC	48.2	<0.001	1		53.8	<0.001	1
NKSCC	67.9		0.596 (0.523, 0.679)	<0.001	71.1		0.582 (0.505, 0.670)	<0.001
BSCC	61.8		0.494 (0.285, 0.858)	0.012	66.8		0.491 (0.270, 0.895)	0.020
T stage^b
T1 + T2	67.5	<0.001	1		72.0	<0.001	1
T3	53.4		1.785 (1.525, 2.089)	<0.001	57.4		1.877 (1.581, 2.227)	<0.001
T4	46.5		2.178 (1.878, 2.527)	<0.001	50.4		2.262 (1.924, 2.659)	<0.001
N stage^c
N0 + N1	62.8	<0.001	1		67.7	<0.001	1
N2	57.5		1.311 (1.135, 1.514)	<0.001	60.9		1.351 (1.156, 1.580)	<0.001
N3	47.4		1.625 (1.357, 1.945)	<0.001	51.1		1.630 (1.342, 1.979)	<0.001
M stage
M0	63.5	<0.001	1		68.1	<0.001	1
M1	23.5		2.888 (2.463, 3.386)	<0.001	25.5		3.204 (2.711, 3.786)	<0.001
Surgery
Recommended	65.9	0.006	1		71.5	0.004	1
Not recommended/unknown	58.2		1.274 (1.035, 1.568)	0.022	62.3		1.261 (1.001, 1.588)	0.049
Radiotherapy
Yes	66.9	<0.001	1		71.8	<0.001	1
No	56.3		1.230 (1.044, 1.449)	0.013	60.4		1.297 (1.082, 1.554)	0.005
Chemotherapy
Yes	62.1	<0.001	1		65.9	<0.001	1
No/unknown	45.6		2.437 (2.083, 2.850)	<0.001	52.4		2.461 (2.071, 2.925)	<0.001

BSCC, basaloid squamous cell carcinoma; CI, confidence interval; CSS, cancer-specific survival; HR, hazard ratio; KSCC, keratinizing squamous cell carcinoma; M, distant metastasis; N, node; NKSCC, nonkeratinizing carcinoma; NPC, nasopharyngeal carcinoma; OS, overall survival; T, tumor. ^aThe 5-year OS and CSS for subjects of unknown race were 73.4% and 77.7%, respectively. ^bT1, nasopharynx, oropharynx, or nasal cavity; T2, parapharyngeal extension; T3, bony structures and/or paranasal sinuses; T4, intracranial extension and/or cranial nerves, hypopharynx, orbit, or infratemporal fossa/masticatory space. ^cN0, none; N1, unilateral cervical and/or unilateral or bilateral retropharyngeal node(s), ≤6 cm in greatest dimension, above supraclavicular fossa; N2, bilateral cervical node(s), ≤6 cm in greatest dimension, above supraclavicular fossa; N3, N3a: >6 cm in greatest dimension, above supraclavicular fossa; N3b: in supraclavicular fossa.