Table 3.
Univariate and multivariate Cox regression analyses for disease‐specific survival in PSCC patients
| Univariate analysis | Multivariate analysis # | |||
|---|---|---|---|---|
| Characteristics | HR (95% CI) | P value | HR (95% CI) | P value |
| Age (≥54 vs. < 54 years) | 1.075 (0.554‐2.088) | 0.830 | N/A | N/A |
| Phimosis (present vs. absent) | 0.899 (0.634‐1.274) | 0.549 | N/A | N/A |
| T stage (T2‐4 vs. T1) | 2.403 (1.049‐5.503) | 0.032 | N/A | N/A |
| N stage (N1‐3 vs. N0) | 14.424 (5.558‐37.433) | <0.001 | 7.130 (2.570‐19.784) | <0.001 |
| Pathologic grade (G2‐3 vs. G1) | 4.608 (2.251‐9.434) | <0.001 | 2.203 (1.042‐4.658) | 0.039 |
| IDO1 H‐score in cancer cells (≥1.15 vs. < 1.15) | 4.956 (2.524‐9.729) | <0.001 | N/A | N/A |
| IDO1+ TIIC density (≥8.5% vs. < 8.5%) | 1.546 (0.791‐3.024) | 0.199 | N/A | N/A |
| CD8+ TIL density (≥9.5% vs. < 9.5%) | 3.366 (1.575‐7.194) | 0.001 | 2.033 (0.928‐4.454) | 0.076 |
| Peripheral blood WBC count (≥7.805 × 109/L vs. < 7.805 × 109/L) | 1.424 (0.708‐2.864) | 0.321 | N/A | N/A |
| Peripheral blood neutrophil count (≥4.22 × 109/L vs. < 4.22 × 109/L) | 2.804 (1.152‐6.822) | 0.023 | N/A | N/A |
| Peripheral blood lymphocyte count (≥1.75 × 109/L vs. < 1.75 × 109/L) | 0.424 (0.209‐0.859) | 0.017 | N/A | N/A |
| Peripheral blood NLR (≥3.25 vs. < 3.25) | 3.070 (1.512‐6.234) | 0.002 | 2.780 (1.066‐7.215) | 0.036 |
| Serum Kyn concentration (≥2.04 µmol/L vs. < 2.04 µmol/L) | 4.548 (2.220‐9.315) | <0.001 | N/A | N/A |
| Serum Trp concentration (≥60.4 µmol/L vs. < 60.4 µmol/L) | 0.458 (0.228‐0.921) | 0.025 | N/A | N/A |
| Serum KTR (≥0.032 vs. < 0.032) | 6.818 (2.960‐15.705) | <0.001 | 2.773 (1.134‐6.778) | 0.025 |
| Serum A/G ratio (≥1.7 vs. < 1.7) | 0.664 (0.286‐1.540) | 0.34 | N/A | N/A |
Abbreviations: IDO1, Indoleamine 2,3‐dioxygenase 1; TIIC, tumor‐infiltrating immune cell; CD8, cluster of differentiation 8; TIL: tumor‐infiltrating lymphocyte; Kyn, kynurenine; Trp, tryptophan; KTR, Kyn/Trp ratio; WBC, white blood cells; NLR, Neutrophil to lymphocyte ratio; A/G, Albumin/Globulin; HR, hazard radio; CI, confidence interval; PSCC, penile squamous cell carcinoma; N/A, not applicable.
Method = Backward stepwise (conditional LR). Variates with P value ≤0.05 in univariate analysis, serum Kyn and Trp concentrations (covered by serum KTR), and blood neutrophil and lymphocyte counts (covered by blood NLR) were all excluded from multivariate Cox regression analysis. IDO1 H‐score in cancer cells and T stage were included in multivariate Cox regression analysis, but they were, in turn, removed out of analysis in the procedure of backward stepwise.