Table 3. Multivariate analyses of pre- and post-operative parameters and IHC staining inferences.

Cox proportional hazard analysis was performed by including: 1. only the pre-operative (i.e., age, PSA, and clinical stage) and post-operative (i.e., Gleason sum, EPE, margin +/−, and SV invasion, lymph node status) parameters; 2. Pre-and post-operative parameters and IL-8 staining score (IL-8 whole model); 3. Margin, Gleason sum and IL-8 staining score (IL-8 parsimonious model); 4. Pre- and post operative parameters and OPN staining score (OPN whole model); 3. Margin, Gleason sum and OPN staining score (OPN parsimonious model); 5. Pre- and post-operative parameters and OPN and IL-8 staining scores included as individual parameters (OPN and IL-8 whole model); 6. Margin, Gleason sum and OPN and IL-8 staining scores (OPN and IL-8 parsimonious model). The whole model analyses were also performed by including the Gleason sum as a categorical variable (Gleason sum < 8 or ≥ 8). The significant parameters (P < 0.05) selected by the model are shown. In all of the analyses, IL-8, OPN or IL-8 and OPN staining scores were included as continuous variables.

Parameter	Chi-Square	P-value	Risk Ratio	95% CI
No IL-8 and/or OPN included (Whole model)
Margin	6.21	0.013	1.59	1.10 – 2.34
No IL-8 and/or OPN included (Whole model, Gleason categorized)
Margin	6.09	0.014	1.58	1.10 – 2.33
Gleason categorized	5.06	0.025	1.51	1.06 – 2.18
IL-8 (Whole model; Gleason continuous)
Margin	4.6	0.032	1.51	1.04 – 2.25
IL-8 (Whole Model; Gleason categorized)
Margin	4.75	0.029	1.52	1.04 – 2.28
Gleason Categorized	3.88	0.049	1.46	1.00 – 2.13
IL-8 (Parsimonious model; Gleason categorized)
Margin	10.93	< 0.001	1.74	1.25 – 2.51
Gleason Categorized	10.84	0.001	1.7	1.24 – 2.34
OPN (Whole model; Gleason continuous)
Margin	5.75	0.017	1.55	1.08 – 2.29
OPN	7.88	0.005	1.00*	1.00 – 1.01
OPN (Whole model; Gleason categorized)
Margin	5.83	0.016	1.55	1.08 – 2.29
OPN	6.75	0.009	1.00*	1.00 – 1.01
OPN (Parsimonious model; Gleason categorized)
Margin	13.51	< 0.001	1.78	1.29 – 2.54
Gleason categorized	6.13	0.013	1.47	1.08 – 2.02
OPN	9.19	0.002	1.01*	1.00 – 1.01
OPN and IL-8 (Whole model; Gleason continuous)
Margin	5.16	0.023	1.52	1.06 – 2.25
OPN	7.36	0.007	1.01*	1.00 – 1.01
OPN and IL-8 (Whole model; Gleason categorized)
Margin	5.27	0.022	1.53	1.07 – 2.26
OPN	6.46	0.011	1.01*	1.00 – 1.01
OPN and IL-8 (Parsimonious model; Gleason categorized)
Margin	12.16	< 0.001	1.81	1.27 – 2.54
OPN	8.5	0.004	1.01*	1.00 – 1.01
Gleason ≥ 8	4.75	0.029	1.44	1.04– 2.00

^*Change in risk ratio per unit change in OPN staining score.