Table 1. Patient and tumor characteristics of breast cancer patients grouped by surgery before and after propensity score matching (N=5,146).
| Characteristics | Pre-matching | Post-Matching | ||||
|---|---|---|---|---|---|---|
| Non-surgery (N=3,432) | Surgery (N=1,714) | P | Non-surgery (N=1,714) | P | ||
| Age, years | <0.001* | 0.008* | ||||
| <50 | 688 (20.0) | 530 (30.9) | 448 (26.1) | |||
| 50–70 | 2,082 (60.7) | 955 (55.7) | 1,018 (59.4) | |||
| >70 | 662 (19.3) | 229 (13.4) | 248 (14.5) | |||
| Race | 0.482 | 0.355 | ||||
| Black | 527 (15.4) | 266 (15.5) | 266 (15.5) | |||
| White | 2,658 (77.4) | 1,309 (76.4) | 1,331 (77.7) | |||
| Other | 247 (7.2) | 139 (8.1) | 117 (6.8) | |||
| Grade | <0.001* | 0.073 | ||||
| I | 317 (9.2) | 129 (7.5) | 150 (8.8) | |||
| II | 1,355 (39.5) | 704 (41.1) | 766 (44.7) | |||
| III | 889 (25.9) | 765 (44.6) | 686 (40.0) | |||
| IV | 12 (0.3) | 5 (0.3) | 5 (0.3) | |||
| Unknown | 859 (25.0) | 111 (6.5) | 107 (6.2) | |||
| Tumor size | <0.001* | 0.879 | ||||
| <8 cm | 2,448 (71.3) | 1,414 (82.5) | 1,425 (83.1) | |||
| >8 cm | 258 (7.5) | 185 (10.8) | 177 (10.3) | |||
| Unknown | 726 (21.2) | 115 (6.7) | 112 (6.5) | |||
| Subtype | <0.001* | 0.402 | ||||
| HER2 positive | 131 (3.8) | 108 (6.3) | 94 (5.5) | |||
| LuminalA | 2,560 (74.6) | 1,164 (67.9) | 1,208 (70.5) | |||
| LuminalB | 503 (14.7) | 281 (16.4) | 266 (15.5) | |||
| TNBC | 238 (6.9) | 161 (9.4) | 146 (8.5) | |||
| Radiation | <0.001* | <0.001* | ||||
| No | 3,165 (92.2) | 806 (47.0) | 1,584 (92.4) | |||
| Yes | 267 (7.8) | 908 (53.0) | 130 (7.6) | |||
| Chemotherapy | <0.001* | 0.401 | ||||
| No | 1,825 (53.2) | 540 (31.5) | 564 (32.9) | |||
| Yes | 1,607 (46.8) | 1,174 (68.5) | 1,150 (67.1) | |||
Values are expressed as n (%) unless otherwise indicated. *, Two-sided P values <0.05.