Table 6.

Cox proportional regression analysis of associations between clinical characteristics and OS in 3893 patients with advanced NPC

Characteristic	OS rate (%)		Unadjusted HR	95% CI	P value	Adjusted HRa	95% CI	P value
	5-year	95% CI
Therapeutic modality
RT	64.8	61.7–67.6	1.00	Reference		1.00	Reference
RCT	75.6	73.8–77.3	0.67	0.59–0.76	<0.001	0.64	0.56–0.72	<0.001
Proposed classification
EC	78.3	76.5–80.0	1.00	Reference		1.00	Reference
MSEC	69.1	65.4–72.5	1.48	1.27–1.72	<0.001	1.43	1.22–1.67	<0.001
SC	57.6	52.8–62.1	2.24	1.91–2.62	<0.001	2.13	1.81–2.51	<0.001
SCC	46.4	37.8–54.5	3.14	2.49–3.96	<0.001	3.99	2.97–5.35	<0.001
Age
≤47 years	77.7	75.7–79.6	1.00	Reference		1.00	Reference
>47 years	66.8	64.4–69.1	1.58	1.39–1.78	<0.001	1.51	1.34–1.71	<0.001
Sex
Male	71.5	69.7–73.3	1.00	Reference		1.00	Reference
Female	75.2	72.1–78.0	0.81	0.69–0.93	0.003	0.82	0.71–0.95	0.008
Clinical stage
III	76.8	74.7–78.8	1.00	Reference		1.00	Reference
IV	68.3	66.0–70.5	1.38	1.22–1.56	<0.001	1.48	1.31–1.68	<0.001
WHO classification
NKUC	72.6	70.8–74.2	1.00	Reference		1.00	Reference
NKDC	73.2	69.5–76.7	0.98	0.83–1.15	0.780	0.97	0.81–1.15	0.690
KSCC	60.9	47.7–71.9	1.66	1.13–2.41	0.009	0.47	0.29–0.76	0.002

NPC nasopharyngeal carcinoma, OS overall survival, CI confidence interval, HR hazard ratio, RT radiotherapy, RCT radiochemotherapy, EC epithelial carcinoma, MSEC mixed sarcomatoid-epithelial carcinoma, SC sarcomatoid carcinoma, SCC squamous cell carcinoma, WHO World Health Organization, NKUC non-keratinizing undifferentiated carcinoma, NKDC non-keratinizing differentiated carcinoma, KSCC keratinizing squamous cell carcinoma

^aAll models were adjusted for the proposed classification, age, sex, therapeutic modality, clinical stage, and WHO classification