Table 2. Univariate and multivariate Cox analyses of OS in 103 patients operated for PC according to pre-treatment concentrations of plasma YKL-40, IL-6, serum CA 19-9, age, sex, and stage.

	Univariate			Multivariate 1			Multivariate 2
	HR	95% CI	P-value	HR	95% CI	P-value	HR	95% CI	P-value
Age pr 10 years	1.27	1.02–1.56	0.030	1.17	0.88–1.56	0.29	1.26	0.94–1.68	0.13
Sex F vs. M	0.68	0.45–1.04	0.074	0.79	0.46–1.36	0.40	0.74	0.43–1.29	0.29
Stage#	1.65	0.98–2.77	0.060	1.07	0.52–2.24	0.85	1.12	0.54–2.32	0.76
YKL-40Hi vs. loN = 142§	1.49	0.93–2.38	0.084	0.69	0.36–1.33	0.26
IL-6Hi vs. loN = 122§§	2.40	1.50–3.86	0.0003	2.03	1.11–3.70	0.021
Ca19.9Hi vs. loN = 107§§§	3.15	1.70–5.85	0.0003	2.51	1.22–5.15	0.013
YKL-40Log2N = 142	1.20	1.01–1.42	0.041				0.89	0.65–1.21	0.44
IL6Log2N = 122	1.16	1.06–1.28	0.0021				1.15	1.00–1.32	0.056
Ca19-9Log2N = 107	1.14	1.05–1.23	0.0013				1.12	1.00–1.24	0.042

HR = Hazard ratio. CI = Confidence interval. Stage is scored as IA+IB+IIA vs. IIB+III. Hi, high concentration; Lo, low concentration.

Multivariate 1: Dichotomized biomarkers. ^§Plasma YKL-40 was dichotomized (high vs. normal according to the age-corrected upper 95% percentage limit of YKL-40 in healthy subjects). ^§§Plasma IL-6 was dichotomized (high vs. normal according to 95% percentage limit of IL-6 in healthy subjects, i.e. cut-off 4.5 ng/l). ^§§§Serum CA 19.9 was dichotomized (high vs. normal according to the cut-off 37 KU/l).

Multivariate 2: The biomarkers are log transformed (log base 2) i.e. hazards are for a twofold difference.