Supplementary table 1. Univariate and multivariate analysis of prognostic factors for overall survival    Univariate analysis   Multivariate analysis   Multivariate analysis

Parameter CategoryHazard ratio P

valueHazard ratio P

valueHazard ratio P

value(95% CI) (95% CI)   (95% CI)Age 1.011 (1.003, 1.018) 0.004 1.009 (1.002, 1.017) 0.018 1.01 (1.003, 1.018) 0.007

Gender Female vs. male 0.927 (0.772, 1.113) 0.416

BMI Normal-BMI 1 1 1Low-BMI 1.405 (1.124, 0.1755) 0.003 1.397 (1.115, 1.748) 0.004 1.380 (1.102, 1.727) 0.005High-BMI 0.713 (0.550, 0.925) 0.011 0.754 (0.580, 0.979) 0.034 0.764 (0.588, 0.993) 0.044

Hemoglobin (<10 g/dL) Yes vs. no 1.352 (1.310, 1.617) <0.001 1.035 (0.858, 1.248) 0.718Albumin (<3.5 g/dL) Yes vs. no 1.572 (1.274, 1.940) <0.001 0.899 (0.71, 1.139) 0.378Weight loss ( >10%) Yes vs. no 1.536 (1.293, 1.824) <0.001 1.133 (0.945, 1.357) 0.178Severe complications (≥ IIIb) Yes vs. no 3.083 (2.180, 4.358) <0.001 1.761 (1.222, 2.538) 0.002 1.897 (1.331, 2.705) <0.001Type of gastrectomy Distal 1 1 1

Total 1.875 (1.562, 2.250) <0.001 1.299 (0.965, 1.747) 0.084 1.249 (1.036, 1.507) 0.020Proximal 1.334 (1.078, 1.652) 0.008 1.416 (0.943, 2.126) 0.093 1.295 (1.037, 1.619) 0.023

Lymphadenectomy D1 1D1+ 0.726 (0.593, 0.889) 0.001 0.993 (0.764, 1.29) 0.958D2 0.803 (0.661, 0.975) 0.027 0.954 (0.752, 1.209) 0.695

Operation time (≥240 min) Yes vs. no 1.277 (1.086, 1.501) 0.003 1.166 (0.979, 1.389) 0.084Blood loss (≥200 ml) Yes vs. no 1.108 (0.927, 1.324) 0.262no. of Lymph nodes Yes vs. no 0.780 (0.646, 0.942) 0.01 0.762 (0.615, 0.944) 0.013 0.788 (0.647, 0.959) 0.018retrieved (≥15)Postoperative hospital stay Yes vs. no 1.213 (1.028, 1.430) 0.022 1.144 (0.961, 1.361) 0.130(≥10 days)Potentially curative Yes vs. no 0.265 (0.218, 0.323) <0.001 0.634 (0.496, 0.811) <0.001 0.619 (0.487, 0.786) <0.001resection (R0)Tumor location Upper 1 1

Middle 0.812 (0.624, 1.056) 0.119 0.877 (0.643, 1.197) 0.409Lower 0.739 (0.618, 0.885) 0.001 1.132 (0.814, 1.576) 0.461Whole stomach 3.366 (2.117, 5.352) <0.001 1.528 (0.908, 2.571) 0.110

Depth of infiltration T1 1 1 1T2 1.754 (1.093, 2.817) 0.02 1.136 (0.701, 1.844) 0.604 1.155 (0.712, 1.874) 0.559T3 4.446 (2.501, 7.907) <0.001 2.517 (1.387, 4.566) 0.002 2.542 (1.404, 4.604) 0.002T4 6.188 (4.278, 8.950) <0.001 2.447 (1.634, 3.665) <0.001 2.472 (1.652, 3.7) <0.001

Lymph node involvement N0 1 1 1N1 2.154 (1.602, 2.896) <0.001 1.792 (1.321, 2.429) <0.001 1.804 (1.332, 2.442) <0.001N2 2.687 (2.014, 3.583) <0.001 1.913 (1.409, 2.596) <0.001 1.887 (1.392, 2.557) <0.001N3 6.985 (5.487, 8.892) <0.001 4.518 (3.427, 5.956) <0.001 4.546 (3.458, 5.976) <0.001

Distance metastasis Yes vs. no 4.159 (3.397, 5.091) <0.001   1.683 (1.311, 2.16) <0.001   1.663 (1.3, 2.125) <0.001

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