Multivariate analysis of LRFS, RFS, and OS according to tumor stage
| Factors | LRFS | RFS | OS | |||
|---|---|---|---|---|---|---|
| HR (95% CI) | P value* | HR (95% CI) | P value* | HR (95% CI) | P value* | |
| Stage II | ||||||
| Age | ||||||
| ≤ 60 years | 1 | 0.157 | 1 | 0.142 | 1 | 0.044 |
| > 60 years | 2.07 (0.75–5.70) | 1.97 (0.79–4.89) | 2.78 (1.02–7.53) | |||
| N classification | ||||||
| N0 | 1 | 0.002 | 1 | <0.001 | 1 | 0.024 |
| Nx | 3.53 (1.57–7.94) | 3.70 (1.81–7.58) | 2.55 (1.12–5.76) | |||
| Preop CA 19-9 level | ||||||
| ≤37 U/mL | 1 | 0.181 | 1 | 0.125 | 1 | 0.580 |
| >37 U/mL | 1.78 (0.76–4.19) | 1.81 (0.84–3.86) | 1.30 (0.51–3.29) | |||
| Postop CA 19-9 level | ||||||
| ≤ 37 U/mL | 1 | 0.048 | 1 | 0.094 | 1 | 0.038 |
| >37 U/mL | 3.60 (1.01–12.85) | 2.78 (0.84–9.21) | 4.27 (1.08–16.91) | |||
| Resection margin | ||||||
| Negative | 1 | 0.001 | 1 | 0.001 | 1 | 0.002 |
| Positive | 11.11 (2.70–45.65) | 10.82 (2.78–42.10) | 9.84 (2.25–42.98) | |||
| LVSI | ||||||
| No | 1 | 0.217 | 1 | 0.405 | 1 | 0.419 |
| Yes | 1.64 (0.74–3.61) | 1.35 (0.66–2.78) | 1.36 (0.64–2.92) | |||
| PNI | ||||||
| No | 1 | 0.005 | 1 | <0.001 | 1 | <0.001 |
| Yes | 3.25 (1.42–7.40) | 3.85 (1.86–7.98) | 4.16 (1.91–9.07) | |||
| Extent of surgical resection | ||||||
| Non-radical | 1 | 0.278 | 1 | 0.532 | 1 | 0.517 |
| Radical | 0.55 (0.18–1.61) | 0.74 (0.29–1.87) | 0.71 (0.26–1.97) | |||
| Stage III–IV | ||||||
| Age | ||||||
| ≤ 60 years | 1 | 0.895 | 0.702 | 1 | 0.108 | |
| > 60 years | 0.97 (0.63–1.48) | 1.07 (0.75–1.53) | 1.37 (0.93–2.03) | |||
| T classification | ||||||
| T2 | 1 | 0.040 | 1 | 0.048 | 1 | 0.054 |
| T3–4 | 1.64 (1.02–2.64) | 1.48 (1.00–2.19) | 1.51 (0.99–2.32) | |||
| N classification | ||||||
| N0 | 1 | 1 | 1 | |||
| N1 | 2.02 (1.10–3.68) | 0.022 | 1.77 (1.08–2.91) | 0.023 | 1.68 (0.96–2.94) | 0.066 |
| N2 | 4.30 (2.22–8.29) | <0.001 | 3.91 (2.24–6.82) | <0.001 | 4.25 (2.31–7.79) | <0.001 |
| Nx | 39.95 (9.33–170.98) | <0.001 | 21.56 (5.73–81.05) | <0.001 | 7.85 (1.62–37.84) | 0.010 |
| Preop CA 19-9 level | ||||||
| ≤ 37 U/mL | 1 | 0.789 | 1 | 0.895 | 1 | 0.128 |
| > 37 U/mL | 1.06 (0.69–1.62) | 0.97 (0.67–1.40) | 0.73 (0.49–1.09) | |||
| Postop CA 19-9 level | ||||||
| ≤37 U/mL | 1 | 0.002 | 1 | <0.001 | 1 | <0.001 |
| >37 U/mL | 2.18 (1.33–3.56) | 2.76 (1.80–4.24) | 2.49 (1.59–3.89) | |||
| Histologic differentiation | ||||||
| WD/MD | 1 | 0.402 | 1 | 0.126 | 1 | 0.229 |
| PD | 1.20 (0.78–1.83) | 1.31 (0.92–2.19) | 1.26 (0.86–1.85) | |||
| Resection margin | ||||||
| Negative | 1 | 0.889 | 1 | 0.153 | 1 | 0.320 |
| Positive | 1.05 (0.48–2.31) | 1.54 (0.85–2.80) | 1.36 (0.74–2.50) | |||
| LVSI | ||||||
| No | 1 | 0.055 | 1 | 0.065 | 1 | 0.019 |
| Yes | 1.65 (0.98–2.75) | 1.46 (0.97–2.19) | 1.74 (1.09–2.77) | |||
| PNI | ||||||
| No | 1 | 0.123 | 1 | 0.241 | 1 | 0.051 |
| Yes | 1.42 (0.90–2.25) | 1.25 (0.86–1.81) | 1.52 (0.99–2.31) | |||
| Extent of surgical resection | ||||||
| Non-radical | 1 | 0.010 | 1 | 0.169 | 1 | 0.259 |
| Radical | 0.39 (0.19–0.79) | 0.62 (031–1.22) | 0.65 (0.30–1.37) | |||
| Adjuvant treatment | ||||||
| No-AT | 1 | 1 | 1 | |||
| CTx | 0.80 (0.50–1.29) | 0.366 | 0.91 (0.60–1.39) | 0.687 | 0.78 (0.51–1.21) | 0.280 |
| CRT | 0.28 (0.15–0.51) | <0.001 | 0.52 (0.33–0.82) | 0.006 | 0.42 (0.25–0.70) | 0.001 |
LRFS, locoregional recurrence-free survival; RFS, recurrence-free survival; OS, overall survival; HR, hazard ratio; CI, confidence interval; Preop, preoperative; Postop, postoperative; CA 19-9, carbohydrate antigen 19-9; LVSI, lymphovascular space invasion; PNI, perineural invasion; WD, well differentiation; MD, moderate differentiation; PD, poor differentiation; No-AT, no adjuvant therapy; CTx, chemotherapy; CRT, chemoradiotherapy. *Cox proportional hazards model.