Table 1. Characteristics of Patients From the NCDB and SUCCESS Cohorts Grouped by CTC Statusa.
| Variable | NCDB Cohort | SUCCESS Cohort | ||||||
|---|---|---|---|---|---|---|---|---|
| CTC Negative (n = 1298) | CTC Positive (n = 399) | P Value | SMD | CTC Negative (n = 1222) | CTC Positive (n = 294) | P Value | SMD | |
| Age, median (IQR), y | 63.0 (53.0-71.0) | 61.0 (52.0-70.0) | .02 | 0.12 | 52.0 (45.0-60.0) | 54.0 (45.0-61.0) | .36 | 0.04 |
| Follow-up, median (IQR), mo | 37.7 (26.4-51.5) | 40.4 (28.7-54.0) | .02 | 0.14 | 64.3 (59.9-69.6) | 64.2 (59.6-72.1) | .91 | 0.02 |
| Tumor stage | ||||||||
| 1 | 1002 (77.2) | 290 (72.7) | .08 | 0.10 | 581 (47.5) | 128 (43.5) | .24 | 0.08 |
| 2 | 296 (22.8) | 109 (27.3) | 641 (52.5) | 166 (56.5) | ||||
| Nodal stage | ||||||||
| 0 | 1244 (95.8) | 366 (91.7) | .002 | 0.17 | 511 (41.8) | 127 (43.2) | .72 | 0.03 |
| Microscopic/1b | 54 (4.2) | 33 (8.3) | 711 (58.2) | 167 (56.8) | ||||
| Grade | ||||||||
| 1 | 343 (26.4) | 124 (31.1) | .14 | 0.11 | 66 (5.4) | 11 (3.7) | .47 | 0.08 |
| 2 | 592 (45.6) | 178 (44.6) | 548 (44.8) | 138 (46.9) | ||||
| 3 | 363 (28.0) | 97 (24.3) | 608 (49.8) | 145 (49.3) | ||||
| Histologic finding | ||||||||
| IDC | 1046 (80.6) | 297 (74.4) | .02 | 0.16 | 1024 (83.8) | 242 (82.3) | .79 | 0.04 |
| ILC/mixed | 182 (14.0) | 78 (19.5) | 111 (9.1) | 29 (10.0) | ||||
| Other | 70 (5.4) | 24 (6.0) | 87 (7.1) | 23 (7.8) | ||||
| ER status | ||||||||
| Positive | 1080 (83.2) | 365 (91.5) | <.001 | 0.25 | 810 (66.3) | 205 (69.7) | .27 | 0.07 |
| Negative | 218 (16.8) | 34 (8.5) | 412 (33.7) | 89 (30.3) | ||||
| PR status | ||||||||
| Positive | 950 (73.2) | 324 (81.2) | .001 | 0.19 | 768 (62.8) | 195 (66.3) | .28 | 0.07 |
| Negative | 348 (26.8) | 75 (18.8) | 454 (37.2) | 99 (33.7) | ||||
| ERBB2 status | ||||||||
| Negative | 1185 (91.3) | 345 (86.5) | .007 | 0.15 | 927 (75.9) | 224 (76.2) | .94 | 0.008 |
| Positive | 113 (8.7) | 54 (13.5) | 295 (24.1) | 70 (23.8) | ||||
| Surgery | ||||||||
| BCS | 777 (59.9) | 241 (60.4) | .89 | 0.01 | 940 (76.9) | 219 (74.5) | .40 | 0.06 |
| Mastectomy | 521 (40.1) | 158 (39.6) | 282 (23.1) | 75 (25.5) | ||||
| Radiotherapy | ||||||||
| No | 563 (43.4) | 172 (43.1) | .95 | 0.005 | 216 (17.7) | 46 (15.6) | .44 | 0.05 |
| Yes | 735 (56.6) | 227 (56.9) | 1006 (82.3) | 248 (84.4) | ||||
| Hormone therapy | ||||||||
| No | 372 (28.7) | 86 (21.5) | .006 | 0.16 | 354 (29.0) | 84 (28.6) | .94 | 0.009 |
| Yes | 926 (71.3) | 313 (78.4) | 868 (71.0) | 210 (71.4) | ||||
| Chemotherapy | ||||||||
| No | 902 (69.5) | 279 (69.9) | .92 | 0.009 | 0 | 0 | >.99 | <0.001 |
| Yes | 396 (30.5) | 120 (30.1) | 1222 (100) | 294 (100) | ||||
| Trastuzumabc | ||||||||
| No | NA | NA | NA | NA | 962 (78.7) | 234 (79.6) | .81 | 0.02 |
| Yes | NA | NA | NA | NA | 260 (21.3) | 60 (20.4) | ||
Abbreviations: BCS, breast-conserving surgery; CTC, circulating tumor cell; ER, estrogen receptor; IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; IQR, interquartile range; LVI, lymphovascular invasion; NA, not applicable; NCDB, National Cancer Database; PR, progesterone receptor; SMD, standardized mean difference; SUCCESS, Simultaneous Study of Gemcitabine-Docetaxel Combination Adjuvant Treatment as well as Extended Bisphosphonate and Surveillance.
a
Significance determined by Fisher exact test or Kruskal-Wallis test. Percentages have been rounded and may not total 100.
b
Defined as microscopic in the NCDB cohort.
c
Data were not available for the NCDB cohort.