Table 2.
Univariable cox proportional hazards analysis for overall survival of gastric cancer patients before and after propensity score matching
| Characteristics | Before matching n = 1034 | After matching n = 573 | ||
|---|---|---|---|---|
| Statistics | HR (95% CI) P value | Statistics | HR (95% CI) P value | |
| Age, years, mean (SD) | 61.72 ± 11.20 | 1.01 (1.00, 1.01) .121 | 61.78 ± 10.86 | 1.01 (1.00, 1.02) .013 |
| Gender | ||||
| Male | 789 (76.31%) | 1.00 (Ref.) | 429 (74.87%) | 1.00 (Ref.) |
| Female | 245 (23.69%) | 1.11 (0.92, 1.33) .279 | 144 (25.13%) | 1.10 (0.88, 1.38) .401 |
| Tumor size, cm, mean (SD) | 5.92 ± 3.42 | 1.10 (1.08, 1.12) <.001 | 6.18 ± 3.60 | 1.08 (1.06, 1.11) <.001 |
| Tumor location | ||||
| Upper | 297 (28.72%) | 1.00 (Ref.) | 165 (28.80%) | 1.00 (Ref.) |
| Middle | 184 (17.79%) | 1.25 (0.99, 1.58) .066 | 102 (17.80%) | 1.03 (0.76, 1.39) .854 |
| Lower | 434 (41.97%) | 0.98 (0.80, 1.20) .845 | 239 (41.71%) | 0.89 (0.69, 1.14) .358 |
| Two regions or Entire | 119 (11.51%) | 2.64 (2.06, 3.38) <.001 | 67 (11.69%) | 2.00 (1.45, 2.75) <.001 |
| Surgical method | ||||
| Open surgery | 393 (38.01%) | 1.00 (Ref.) | 151 (26.35%) | 1.00 (Ref.) |
| Laparoscopic surgery | 641 (61.99%) | 1.23 (1.04, 1.45) .014 | 422 (73.65%) | 0.79 (0.63, 0.99) .037 |
| Gastrectomy | ||||
| Proximal | 281 (27.18%) | 1.00 (Ref.) | 148 (25.83%) | 1.00 (Ref.) |
| Distal | 419 (40.52%) | 1.15 (0.93, 1.41) .193 | 232 (40.49%) | 1.14 (0.88, 1.49) .324 |
| Total | 334 (32.30%) | 1.75 (1.42, 2.15) <.001 | 193 (33.68%) | 1.51 (1.16, 1.96) .002 |
| Lymphovascular invasion | ||||
| Negative | 724 (70.02%) | 1.00 (Ref.) | 397 (69.28%) | 1.00 (Ref.) |
| Positive | 310 (29.98%) | 2.06 (1.75, 2.42) <.001 | 176 (30.72%) | 2.01 (1.63, 2.48) <.001 |
| Perineural invasion | ||||
| Negative | 766 (74.08%) | 1.00 (Ref.) | 437 (76.27%) | 1.00 (Ref.) |
| Positive | 268 (25.92%) | 1.41 (1.19, 1.67) <.001 | 136 (23.73%) | 1.45 (1.16, 1.82) .001 |
| Histologic grade | ||||
| Differentiated | 432 (41.78%) | 1.00 (Ref.) | 229 (39.97%) | 1.00 (Ref.) |
| Undifferentiated | 602 (58.22%) | 1.56 (1.33, 1.84) <.001 | 344 (60.03%) | 1.53 (1.24, 1.89) <.001 |
| Depth of invasion | ||||
| T1 | 64 (6.19%) | 1.00 (Ref.) | 17 (2.97%) | 1.00 (Ref.) |
| T2 | 114 (11.03%) | 1.86 (1.01, 3.43) .047 | 38 (6.63%) | 1.99 (0.68, 5.87) .209 |
| T3 | 128 (12.38%) | 3.32 (1.86, 5.92) <.001 | 61 (10.65%) | 2.54 (0.91, 7.13) .076 |
| T4a | 591 (57.16%) | 4.93 (2.88, 8.43) <.001 | 384 (67.02%) | 3.66 (1.36, 9.82) .010 |
| T4b | 137 (13.25%) | 9.13 (5.23, 15.96) <.001 | 73 (12.74%) | 5.53 (2.01, 15.22) .001 |
| Lymph node metastasis | ||||
| N0 | 243 (23.50%) | 1.00 (Ref.) | 110 (19.20%) | 1.00 (Ref.) |
| N1 | 187 (18.09%) | 1.35 (0.99, 1.85) .056 | 96 (16.75%) | 1.06 (0.71, 1.59) .772 |
| N2 | 226 (21.86%) | 2.44 (1.86, 3.20) <.001 | 149 (26.00%) | 1.86 (1.33, 2.61) <.001 |
| N3a | 244 (23.60%) | 4.69 (3.62, 6.08) <.001 | 153 (26.70%) | 3.46 (2.49, 4.80) <.001 |
| N3b | 134 (12.96%) | 9.24 (6.96, 12.27) <.001 | 65 (11.34%) | 7.81 (5.33, 11.46) <.001 |
| TD | ||||
| Negative | 794 (76.79%) | 1.00 (Ref.) | 382 (66.67%) | 1.00 (Ref.) |
| Positive | 240 (23.21%) | 1.75 (1.47, 2.08) <.001 | 191 (33.33%) | 1.28 (1.04, 1.58) .019 |
Data are presented as mean ± SD or n (%).
Abbreviations: Ref, reference; SD, standard deviation; TD, tumor deposit.