Table 1.
Clinicopathological characteristics of ER+PR-HER2- breast cancer cases from SEER and METABRIC cohorts compared with ER+PR+HER2- cases.
| Cohort 1: SEER | CCa | P-valueb | Cohort 2: METABRIC | P-valueb | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| ER+PR+HER2- | ER+PR-HER2- | TNBC | ER+PR+HER2- | ER+PR-HER2- | TNBC | |||||
| N=99,058 (%) | N=13,084 (%) | N=18,714 (%) | N=626 (%) | N=260 (%) | N=169 (%) | |||||
| Median Follow-up (IQR) (mo) | 26 (11-41) | 125.8 (75.3-194.0) | ||||||||
| Age | 18-49 | 23,446 (23.7) | 2,375 (18.2) | 6,007 (32.1) | 0.04 | <0.001 | 113 (18.1) | 21 (8.1) | 52 (31.0) | <0.001 |
| ≥50 | 75,612 (76.3) | 10,709 (81.9) | 12,707 (67.9) | 513 (82.0) | 239 (91.9) | 117 (69.0) | ||||
| Race | White | 79,932 (80.7) | 9,827 (75.1) | 13,250 (70.8) | 0.06* | <0.001 | - | - | - | |
| Black | 8,653 (8.7) | 1,883 (14.4) | 3,892 (20.8) | - | - | - | ||||
| AS/AI/AP | 9,762 (9.9) | 1,278 (9.8) | 1,440 (7.7) | - | - | - | ||||
| N/A | 711 (0.7) | 96 (0.7) | 112 (0.6) | - | - | - | ||||
| Histologic type | IDC | 82,193 (83.0) | 10,787 (82.4) | 16,318 (87.2) | 0.01 | <0.001 | 626 (100.0) | 260 (100.0) | 169 (100.0) | - |
| ILC | 12,183 (12.3) | 1,747 (13.4) | 169 (0.9) | 0 | 0 | 0 | ||||
| Others and N/A | 4,682 (4.7) | 550 (4.2) | 2,227 (11.9) | 0 | 0 | 0 | ||||
| Grade | 1 | 30,398 (30.7) | 2,541 (19.4) | 356 (1.9) | 0.36* | <0.001 | 78 (12.5) | 24 (9.2) | 3 (2.0) | 0.001 |
| 2 | 48,530 (49.0) | 4,814 (36.8) | 2,939 (15.7) | 329 (52.6) | 113 (43.5) | 21 (12.3) | ||||
| 3 | 17,119 (17.3) | 5,228 (40.0) | 14,597 (78.0) | 187 (29.9) | 114 (43.9) | 143 (84.7) | ||||
| Others and N/A | 3,011 (3.0) | 501 (3.8) | 842 (4.5) | 32 (5.1) | 9 (3.5) | 2 (1.0) | ||||
| T stage | T0-1 | 67,342 (68.0) | 7,433 (56.8) | 8,290 (44.3) | 0.22* | <0.001 | 297 (47.4) | 108 (41.5) | 71 (41.9) | 0.014 |
| T2 | 25,747 (26.0) | 4,365 (33.4) | 7,991 (42.7) | 310 (49.5) | 133 (51.2) | 86 (50.7) | ||||
| T3-T4 | 5,908 (6.0) | 1,269 (9.7) | 2,396 (12.8) | 19 (3.0) | 18 (6.9) | 12 (7.4) | ||||
| N/A | 61 (0.1) | 17 (0.1) | 37 (0.2) | 0 (0) | 1 (0.4) | 0 (0.0) | ||||
| LN status | Negative | 70,356 (71.0) | 8,809 (67.3) | 12,332 (65.9) | 0.03 | <0.001 | 378 (60.4) | 129 (49.6) | 90 (53.2) | 0.003 |
| Positive | 28,679 (29.0) | 4,268 (32.6) | 6,363 (34.0) | 248 (39.6) | 131 (50.4) | 79 (46.8) | ||||
| N/A | 23 (0.0) | 7 (0.1) | 19 (0.1) | - | - | - | ||||
| Stage | I | 58,663 (59.2) | 6,383 (48.8) | 6,943 (37.1) | 0.07 | <0.001 | 245 (39.1) | 83 (31.9) | 48 (28.6) | 0.005 |
| II | 30,973 (31.3) | 4,878 (37.3) | 8,759 (46.8) | 354 (56.6) | 153 (58.9) | 104 (61.1) | ||||
| III | 9,411 (9.5) | 1,823 (13.9) | 3,012 (16.1) | 27 (4.3) | 24 (9.2) | 17 (10.3) | ||||
| Chemotherapy | Yes | 30,178 (30.5) | 6,614 (50.6) | 14,766 (78.9) | 0.14 | <0.001 | 55 (8.8) | 27 (10.4) | 88 (52.2) | 0.455 |
| No/ Unknown | 68,880 (69.5) | 6,470 (49.5) | 3,948 (21.1) | 571 (91.2) | 233 (89.6) | 81 (47.8) | ||||
| Radiation | Yes | 57,901 (58.5) | 7,313 (55.9) | 9,581 (51.2) | 0.02 | <0.001 | 395 (63.1) | 163 (62.7) | 128 (75.9) | 0.909 |
| No/Unknown | 41,157 (41.6) | 5,771 (44.1) | 9,133 (48.8) | 231 (36.9) | 97 (37.3) | 41 (24.1) | ||||
| Endocrine therapy | Yes | - | - | - | - | - | 424 (67.7) | 206 (79.2) | 51 (30.1) | 0.001 |
| No/Unknown | - | - | - | 202 (32.3) | 54 (20.8) | 118 (69.9) | ||||
| Surgery | BCS | 61,055 (61.6) | 7,343 (56.1) | 9,451 (50.5) | 0.04 | <0.001 | 290 (46.3) | 101 (38.9) | 81 (47.8) | 0.034 |
| Mastectomy | 35,618 (36.0) | 5,275 (40.3) | 8,346 (44.6) | 333 (53.2) | 155 (59.6) | 86 (50.7) | ||||
| Others and N/A | 2,385 (2.4) | 466 (3.6) | 917 (4.9) | 3 (0.5) | 4 (1.5) | 2 (1.5) | ||||
AS/AI/AP: Alaskan native/American Indian, and Asian/Pacific Islander, and others-unspecified; CC: contingency coefficient; ER: estrogen receptor; HER2: human epidermal growth factor receptor 2; IDC: invasive ductal carcinoma; ILC: invasive lobular carcinoma; IQR: interquartile range; LN: lymph node; METABRIC: Molecular Taxonomy of Breast Cancer International Consortium; N/A: not available; PR: progesterone receptor; SEER: Surveillance, Epidemiology, and End Results; TNBC: triple negative breast cancer.
a Contingency coefficient >0.02 is defined as significant. * is gamma coefficient.
b Pearson's chi-square test was performed between the ER+PR+HER2- and ER+PR-HER2- groups.