The prognostic value of the hypoxia markers CA IX and GLUT 1 and the cytokines VEGF and IL 6 in head and neck squamous cell carcinoma treated by radiotherapy ± chemotherapy

Table 3 Univariate and multivariate analysis for pretreatment IL-6 serum levels (Group B)

	Local control			Regional control			Disease-free survival			Overall survival
	RR	95% CI	P value	RR	95% CI	P value	RR	95% CI	P value	RR	95% CI	P value
Univariate	0.98	1.39–9.78	0.03	1.29	0.37–4.53	0.68	3.24	1.25–8.50	0.05	8.30	2.44–28.50	0.0009
Multivariate	4.06	1.40–11.70	0.009	1.80	0.40–8.17	0.45	3.39	1.22–9.39	0.02	7.61	1.82–31.80	0.005

Univariate and multivariate analysis (Cox proportional hazard model) for IL-6 (> or < median) towards local control, regional control, disease-free survival and overall survival. Significant P values are marked in bold. RR: relative risk. CI: confidence interval.