Table 2.
Uni- and multivariate Cox regression analyses for factors affecting patient survival
| Variables | Univariate | Multivariate | ||||
|---|---|---|---|---|---|---|
| HR | 95 % CI | P value | HR | 95 % CI | P value | |
| Sex | ||||||
| Male | Ref. | Ref. | ||||
| Female | 0.470 | (0.328–0.673) | <0.001 | 0.462 | (0.319–0.668) | <0.001 |
| Age (years) | ||||||
| <75 | Ref. | Ref. | ||||
| ≥75 | 1.793 | (1.114–2.886) | 0.016 | 1.932 | (1.193–3.128) | 0.007 |
| Pathologic differentiation grade | 0.075 | 0.016 | ||||
| Well-differentiated (G1) | Ref. | Ref. | ||||
| Moderately differentiated (G2) | 1.442 | (0.982–2.118) | 0.062 | 1.539 | (1.041–2.277) | 0.031 |
| Poorly or not differentiated (G3) | 1.553 | (1.063–2.269) | 0.023 | 1.764 | (1.196–2.602) | 0.004 |
| Lymphovascular invasion | ||||||
| Yes | Ref. | Ref. | ||||
| No | 0.664 | (0.512–0.862) | 0.002 | 0.738 | (0.566–0.964) | 0.026 |
| Nerve invasion | ||||||
| Yes | Ref. | Ref. | ||||
| No | 0.745 | (0.571–0.971) | 0.03 | 0.953 | (0.724–1.256) | 0.735 |
| Tumor location | 0.079 | |||||
| Upper | Ref. | |||||
| Middle | 1.071 | (0.821–1.397) | 0.611 | |||
| Lower | 0.783 | (0.567–1.081) | 0.137 | |||
| Pathologic T category | ||||||
| T1/T2 | Ref. | Ref. | ||||
| T3/T4 | 2.956 | (1.393–6.272) | <0.001 | 1.938 | (1.427–2.632) | <0.001 |
| 8th-Edition TNM stage | ||||||
| II | Ref. | Ref. | ||||
| III/IV | 2.726 | (1.289–5.766) | 0.009 | 1.766 | (0.798–3.909) | 0.161 |
| Thoracic surgery | ||||||
| MIE | Ref. | |||||
| OE | 1.076 | (0.863–1.342) | 0.515 | |||
| Abdominal surgery | ||||||
| MIE | Ref. | |||||
| OE | 1.086 | (0.865–1.364) | 0.476 | |||
| Clinical treatment method | ||||||
| Surgery alone | Ref. | Ref. | ||||
| Surgery + postoperative CT or RT/CRT | 0.752 | (0.606–0.934) | 0.01 | 0.696 | (0.559–0.866) | 0.001 |
| No. of LNMs | ||||||
| 1 | Ref. | Ref. | ||||
| 2 | 1.391 | (1.120–1.727) | 0.003 | 1.266 | (0.914–1.753) | 0.156 |
| No. of LN stations | ||||||
| 1 | Ref. | Ref. | ||||
| 2 | 1.584 | (1.272–1.973) | <0.001 | 1.166 | (0.835–1.630) | 0.367 |
HR hazard ratio, CI confidence interval, TNM tumor-node-metastasis, MIE minimally invasive esophagectomy, OE open esophagectomy, CT chemotherapy, RT radiotherapy, CRT chemoradiotherapy, LN lymph node, LNM LN metastasis