Table 1.
Characteristics of cohorts defined by surgical approach before and after propensity score matching. Categorical data are presented as n (%) and continuous data as mean ± SD.
| Before matching | After matching | |||||
|---|---|---|---|---|---|---|
| Open (n =1355) | Ml (n =2059) | p | Open (n =889) | Ml (n =889) | p | |
| Age, years | 62.3 ± 12.1 | 61.1 ± 11.4 | 0.003 | 60.6 ± 11.1 | 60.3 ± 11.2 | 0.812 |
| Gender | 0.010 | 0.382 | ||||
| Male | 956 (70.6) | 1535 (74.6) | 657 (73.9) | 674 (75.8) | ||
| Female | 399 (29.4) | 524 (25.4) | 232 (26.1) | 215 (24.2) | ||
| Tumor size (cm) | 4.8 ± 2.9 | 4.6 ± 2.7 | 0.259 | 5.2 ± 2.8 | 5.1 ± 2.7 | 0.230 |
| Differentiation type | <0.001 | 0.474 | ||||
| Differentiated | 451 (33.3) | 887 (43.1) | 398 (44.8) | 383 (43.1) | ||
| Undifferentiated/unknown | 904 (66.7) | 1172 (56.9) | 491 (55.2) | 506 (56.9) | ||
| Tumor location | <0.001 | 0.053 | ||||
| Lower third | 579 (42.7) | 877 (42.5) | 393 (44.2) | 346 (38.9) | ||
| Middle third | 230 (17.0) | 415 (20.2) | 125 (14.1) | 178 (20.0) | ||
| Upper third or GE junction | 418 (30.9) | 510 (24.8) | 263 (29.6) | 243 (27.4) | ||
| Distributed throughout | 128 (9.4) | 257 (12.5) | 108 (12.1) | 122 (13.7) | ||
| Resection extent | 0.574 | 0.388 | ||||
| Distal | 619 (45.7) | 938 (45.6) | 386 (43.4) | 367 (41.3) | ||
| Proximal/total | 736 (54.3) | 1121 (54.4) | 503 (56.6) | 522 (58.7) | ||
| Number of positive LNs | 6.0 ± 9.0 | 6.3 ± 12.5 | 0.420 | 7.5 ± 10.1 | 7.3 ± 9.1 | 0.122 |
| Number of LNs examined | 26.1 ± 13.2 | 32.8 ± 13.4 | 0.409 | 28.2 ± 14.0 | 34.2 ± 13.3 | 0.897 |
| pT stage | <0.001 | 0.123 | ||||
| T1 | 331 (24.5) | 536 (26.0) | 154 (17.3) | 144 (16.2) | ||
| T2 | 148 (10.9) | 234 (11.4) | 98 (11.1) | 85 (9.6) | ||
| T3 | 272 (20.1) | 565 (27.4) | 170 (19.1) | 210 (23.6) | ||
| T4 | 604 (44.5) | 724 (35.2) | 467 (52.5) | 450 (50.6) | ||
| pN stage | 0.652 | 0.741 | ||||
| N0 | 511 (37.8) | 798 (38.8) | 267 (30.0) | 250 (28.1) | ||
| N1 | 205 (15.1) | 294 (14.2) | 131 (14.7) | 127 (14.3) | ||
| N2 | 205 (15.1) | 325 (15.8) | 144 (16.3) | 159 (17.9) | ||
| N3a | 241 (17.8) | 354(17.2) | 176 (19.8) | 189 (21.3) | ||
| N3b | 193 (14.2) | 288 (14.0) | 171 (19.2) | 164 (18.4) | ||
| pTNM stage | 0.138 | 0.471 | ||||
| I | 379 (28.0) | 632 (30.7) | 190 (21.4) | 171 (19.2) | ||
| II | 286 (21.1) | 446 (21.7) | 172 (19.3) | 185 (20.8) | ||
| III | 690 (50.9) | 981 (47.6) | 527 (59.3) | 533 (60.0) | ||
| Postop Chemotherapy | 0.516 | 0.739 | ||||
| Yes | 646 (47.7) | 1005 (48.8) | 463 (52.1) | 470 (52.9) | ||
| No | 709 (52.3) | 1054 (51.2) | 426 (47.9) | 419 (47.1) | ||
| Postop Radiation | <0.001 | 0.247 | ||||
| Yes | 51 (3.8) | 8 (0.4) | 8 (0.9) | 4 (0.4) | ||
| No | 1304 (96.2) | 2051 (99.6) | 881 (99.1) | 885 (99.6) | ||
MI, minimally invasive; GE, gastroesophageal; LNs, lymph nodes; Postop, postoperative.