HPV Infection in Esophageal Squamous Cell Carcinoma and Its Relationship to the Prognosis of Patients in Northern China

Table 4

Multivariate Cox analysis for 5-year survival and progression-free survival in the study patients with esophageal squamous cell carcinoma.

Parameters	Multivariate analysis
	5-yr overall survival			5-yr progression-free survival
	HR	95% CI	P value	HR	95% CI	P value
pT status	2.65	1.39–5.05	0.003	2.09	1.17–3.72	0.01
T1/T2 versus T3/T4
pN status	2.07	1.16–3.72	0.01	2.14	1.24–3.68	0.006
N0 versus N1/N2/N3
TNM stage	1.91	0.28–2.43	0.04	0.48	0.15–2.47	0.03
I/II versus III/IV
Pack-years of smoking	1.84	1.00–3.39	0.06	1.94	1.09–3.44	0.02
<20 versus ≥20
Tumor HPV status	0.37	0.16–0.82	0.01	0.38	0.18–0.77	0.008
Positive versus negative

HR: hazard ratio; CI: confidence interval; a pack-year: the equivalent of smoking one pack of cigarettes per day for 1 year.