Table 1.
Characteristics of patients with OBC before and after PSM.
| Characteristics | Before PSM |
After PSM |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Total (n = 569) | ALND +radiotherapy (n = 247) | Mastectomy + ALND (n = 322) | P | Total (n = 494) | ALND +radiotherapy (n = 247) | Mastectomy + ALND (n = 247) | P | |||
| Year of diagnosis | 1.172 | 0.279 | 0.835 | 0.361 | ||||||
| 2004 - 2010 | 331 (58.2) | 150 (60.7) | 181 (56.2) | 290 (58.7) | 150 (60.7) | 140 (56.7) | ||||
| 2011 - 2015 | 238 (41.8) | 97 (39.3) | 141 (43.8) | 204 (41.3) | 97 (39.3) | 107 (43.3) | ||||
| Age at diagnosis | 4.382 | 0.036 | 0.008 | 0.928 | ||||||
| < 60 | 298 (52.4) | 117 (47.4) | 181 (56.2) | 233 (47.2) | 117 (47.4) | 116 (47) | ||||
| ≥ 60 | 271 (47.6) | 130 (52.6) | 141 (43.8) | 261 (52.8) | 130 (52.6) | 131 (53) | ||||
| ER | 0.506 | 0.776 | 0.528 | 0.768 | ||||||
| Negative | 197 (34.6) | 87 (35.2) | 110 (34.2) | 180 (36.4) | 87 (35.2) | 93 (37.7) | ||||
| Positive | 318 (55.9) | 139 (56.3) | 179 (55.6) | 270 (54.7) | 139 (56.3) | 131 (53) | ||||
| Unknown | 54 (9.5) | 21 (8.5) | 33 (10.2) | 44 (8.9) | 21 (8.5) | 23 (9.3) | ||||
| PR | 2.301 | 0.316 | 1.212 | 0.546 | ||||||
| Negative | 279 (49) | 114 (46.2) | 165 (51.2) | 238 (48.2) | 114 (46.2) | 124 (50.2) | ||||
| Positive | 224 (39.4) | 106 (42.9) | 118 (36.6) | 200 (40.5) | 106 (42.9) | 94 (38.1) | ||||
| Unknown | 66 (11.6) | 27 (10.9) | 39 (12.1) | 56 (11.3) | 27 (10.9) | 29 (11.7) | ||||
| HER2 | 2.767 | 0.251 | 3.836 | 0.147 | ||||||
| Negative | 179 (31.5) | 83 (33.6) | 96 (29.8) | 160 (32.4) | 83 (33.6) | 77 (31.2) | ||||
| Positive | 64 (11.2) | 22 (8.9) | 42 (13.1) | 58 (11.7) | 22 (8.9) | 36 (14.6) | ||||
| Unknown | 326 (57.3) | 142 (57.5) | 184 (57.1) | 276 (55.9) | 142 (57.5) | 134 (54.3) | ||||
| Grade | 2.417 | 0.299 | 1.922 | 0.383 | ||||||
| I-II | 32 (5.6) | 10 (4.1) | 22 (6.8) | 27 (5.5) | 10 (4) | 17 (6.9) | ||||
| III-IV | 113 (19.9) | 47 (19.0) | 66 (20.5) | 93 (18.8) | 47 (19) | 46 (18.6) | ||||
| Unknown | 424 (74.5) | 190 (76.9) | 234 (72.7) | 374 (75.7) | 190 (76.9) | 184 (74.5) | ||||
| Lymph node | 0.597 | 0.742 | 0.113 | 0.945 | ||||||
| N1 | 333 (58.5) | 146 (59.1) | 187 (58.1) | 290 (58.7) | 146 (59.1) | 144 (58.3) | ||||
| N2 | 121 (21.3) | 49 (19.8) | 72 (22.4) | 101 (20.4) | 49 (19.8) | 52 (21.1) | ||||
| N3 | 115 (20.2) | 52 (21.1) | 63 (19.6) | 103 (20.9) | 52 (21.1) | 51 (20.6) | ||||
| RNE | 0.215 | 0.643 | 0.144 | 0.704 | ||||||
| < 10 | 183 (32.2) | 82 (33.2) | 101 (31.4) | 168 (34.0) | 82 (33.2) | 86 (34.8) | ||||
| ≥ 10 | 386 (67.8) | 165 (66.8) | 221 (68.6) | 326 (66.0) | 165 (66.8) | 161 (65.2) | ||||
| Chemotherapy | 0.065 | 0.799 | 0 | 1 | ||||||
| Yes | 451 (79.3) | 197 (79.8) | 254 (78.9) | 394 (79.8) | 197 (79.8) | 197 (79.8) | ||||
| No | 118 (20.7) | 50 (20.2) | 68 (21.1) | 100 (20.2) | 50 (20.2) | 50 (20.2) | ||||
Abbreviations: ALND, axillary lymph node dissection; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; OBC, occult breast cancer; PR, progesterone receptors; PSM, propensity score matching; RNE, regional lymph node examined.