Table 2.
Clinical and Treatment Characteristics, cN1 Breast Cancer Patients who Underwent Surgery following Neoadjuvant Chemotherapy (NACT), National Cancer Data Base (NCDB), 2010–2015 (n=26,009)a,b
| All Patients | Breast/Chest Wall + Lymph Node Radiation | Breast/Chest Wall Radiation | No Radiation | ||
|---|---|---|---|---|---|
| N=26,009 (100%) | N=12,979 (49.9%) | N=6,944 (26.7%) | N=6,086 (23.4%) | P-Value | |
| Grade | |||||
| 1 | 1,075 (4.1%) | 537 (4.1%) | 275 (4%) | 263 (4.3%) | 0.01 |
| 2 | 8,180 (31.5%) | 4,206 (32.4%) | 2,166 (31.2%) | 1,808 (29.7%) | |
| 3 | 14,845 (57.1%) | 7,337 (56.5%) | 3,970 (57.2%) | 3,538 (58.1%) | |
| Unknown | 1,909 (7.3%) | 899 (6.9%) | 533 (7.7%) | 477 (7.8%) | |
| Histology | |||||
| Ductal | 22,715 (87.3%) | 11,226 (86.5%) | 6,155 (88.6%) | 5,334 (87.6%) | 0.01 |
| Lobular | 1,067 (4.1%) | 574 (4.4%) | 247 (3.6%) | 246 (4%) | |
| Other | 218 (0.8%) | 99 (0.8%) | 56 (0.8%) | 63 (1%) | |
| Tumor Subtype/Receptor Group | |||||
| HR+/HER2− | 10,411 (40%) | 5,576 (43%) | 2,743 (39.5%) | 2,092 (34.4%) | <0.001 |
| HER2+ | 8,946 (34.4%) | 4,274 (32.9%) | 2,372 (34.2%) | 2,300 (37.8%) | |
| TNBC | 6,281 (24.1%) | 3,002 (23.1%) | 1,718 (24.7%) | 1,561 (25.6%) | |
| Clinical T Classification | |||||
| cT1 | 4,794 (18.4%) | 2,151 (16.6%) | 1,330 (19.2%) | 1,313 (21.6%) | <0.001 |
| cT2 | 14,730 (56.6%) | 7,193 (55.4%) | 4,039 (58.2%) | 3,498 (57.5%) | |
| cT3 | 6,485 (24.9%) | 3,635 (28%) | 1,575 (22.7%) | 1,275 (20.9%) | |
| Pathological T Classification | |||||
| ypT0 | 6,641 (25.5%) | 3,048 (23.5%) | 1,793 (25.8%) | 1,800 (29.6%) | <0.001 |
| ypT1 | 12,122 (46.6%) | 6,084 (46.9%) | 3,335 (48%) | 2,703 (44.4%) | |
| ypT2 | 5,673 (21.8%) | 2,980 (23%) | 1,437 (20.7%) | 1,256 (20.6%) | |
| ypT3 | 1,471 (5.7%) | 821 (6.3%) | 353 (5.1%) | 297 (4.9%) | |
| ypT4 | 102 (0.4%) | 46 (0.4%) | 26 (0.4%) | 30 (0.5%) | |
| Pathological N Classification | |||||
| ypN0 | 12,341 (47.4%) | 5,423 (41.8%) | 3,531 (50.8%) | 3,387 (55.7%) | <0.001 |
| ypN1 | 13,668 (52.6%) | 7,556 (58.2%) | 3,413 (49.2%) | 2,699 (44.3%) | |
| Response to NACT | |||||
| Breast-only pCR | 1,070 (4.1%) | 584 (4.5%) | 261 (3.8%) | 225 (3.7%) | <0.001 |
| Discordant/Nodal pCR | 150 (0.6%) | 65 (0.5%) | 51 (0.7%) | 34 (0.6%) | |
| Breast Downstage/Nodal pCR | 4,735 (18.2%) | 2,153 (16.6%) | 1,391 (20%) | 1,191 (19.6%) | |
| Breast Downstage/Node-positive | 6,009 (23.1%) | 3,547 (27.3%) | 1,466 (21.1%) | 996 (16.4%) | |
| No stage change | 5,864 (22.5%) | 3,031 (23.4%) | 1,516 (21.8%) | 1,317 (21.6%) | |
| No Breast Change/Nodal pCR | 1,885 (7.2%) | 741 (5.7%) | 557 (8%) | 587 (9.6%) | |
| Overall pCR | 5,571 (21.4%) | 2,464 (19%) | 1,532 (22.1%) | 1,575 (25.9%) | |
| Upstage | 725 (2.8%) | 394 (3%) | 170 (2.4%) | 161 (2.6%) | |
| Type of Breast Surgery | |||||
| Lumpectomy | 9,474 (36.4%) | 4,829 (37.2%) | 3,930 (56.6%) | 715 (11.7%) | <0.001 |
| Mastectomy | 16,535 (63.6%) | 8,150 (62.8%) | 3,014 (43.4%) | 5,371 (88.3%) | |
| Breast Surgery Type*ypN classification | |||||
| Lumpectomy-ypN0 | 4,842 (18.6%) | 2,246 (17.3%) | 2,215 (31.9%) | 381 (6.3%) | <0.001 |
| Lumpectomy-ypN 1 | 4,632 (17.8%) | 2,583 (19.9%) | 1,715 (24.7%) | 334 (5.5%) | |
| Mastectomy-ypN0 | 7,499 (28.8%) | 3,177 (24.5%) | 1,316 (18.9%) | 3,006 (49.4%) | |
| Mastectomy-ypN 1 | 9,036 (34.7%) | 4,973 (38.3%) | 1,698 (24.4%) | 2,365 (38.9%) | |
| Extent of Axillary Surgery (i.e., number of LNs removed and examined) | |||||
| 1–9 LNs | 12,874 (49.5%) | 6,154 (47.4%) | 3,549 (51.1%) | 3,171 (52.1%) | <0.001 |
| ≥ 10 LNs | 13,135 (50.5%) | 6,825 (52.6%) | 3,395 (48.9%) | 2,915 (47.9%) | |
| Positive Lymph Nodes [LNs] | |||||
| 1 (1 – 3) | 2 (1 – 3) | 1 (1 – 2) | 1 (1 – 2) | <0.001 | |
| Endocrine Therapy | |||||
| Adjuvant Endocrine Therapy Only | 12,813 (49.3%) | 7,093 (54.6%) | 3,551 (51.1%) | 2,169 (35.6%) | <0.001 |
| Neoadjuvant Endocrine Therapy | 1,525 (5.9%) | 649 (5%) | 385 (5.5%) | 491 (8.1%) | |
| No Endocrine | 10,671 (41%) | 4,826 (37.2%) | 2,766 (39.8%) | 3,079 (50.6%) | |
a
Limited to patients with post-neoadjuvant chemotherapy nodal classification of ypN0 or ypN1.
b
Percentages represent column proportions for each variable except for the header row subgroups.