Table 1.
Demographic characteristics for invasive breast cancer cases by each of the four investigated categoriesa
| Inflammatory breast cancer (n = 2,014) | Locally advanced breast cancer (n = 1,268) | Metastatic breast cancer (n = 3,059) | Non-T4 breast cancer (n = 73,758) | Total (n = 80,099) | |
| Median (± SD) age at diagnosis (years) | 57.3 ± 14.4 | 64.3 ± 16.3 | 61.9 ± 14.9 | 60.2 ± 13.8 | 60.2 ± 13.9 |
| Race | |||||
| Caucasian | 1,252 (62%) | 783 (62%) | 2,009 (66%) | 52,280 (71%) | 56,324 (70%) |
| African-American | 192 (10%) | 126 (10%) | 287 (9%) | 4,008 (5%) | 4,613 (6%) |
| Hispanic | 412 (20%) | 220 (17%) | 503 (16%) | 10,188 (14%) | 11,323 (14%) |
| Asian | 140 (7%) | 122 (10%) | 241 (8%) | 6,808 (9%) | 7,311 (9%) |
| Other | 18 (0.9%) | 17 (1%) | 19 (0.6%) | 474 (0.6%) | 528 (0.7%) |
| Stage | |||||
| I | - | - | - | 38,571 (52%) | 38,571 (48%) |
| IIA | - | - | - | 21,308 (29%) | 21,308 (27%) |
| IIB | - | - | - | 11,137 (15%) | 11,137 (14%) |
| IIIA | - | - | - | 2,675 (4%) | 2,675 (3%) |
| IIIB | 1,520 (75%) | 1,268 (100%) | - | 67 (<0.1%) | 2,855 (4%) |
| IV | 494 (25%) | 0 (0%) | 3,059 (100%) | 0 (0%) | 3,553 (4%) |
| Tumor grade | |||||
| Grade 1 | 51 (3%) | 82 (6%) | 141 (5%) | 16,458 (22%) | 16,732 (21%) |
| Grade 2 | 433 (22%) | 363 (29%) | 764 (25%) | 28,873 (39%) | 30,433 (38%) |
| Grade 3 | 1,025 (51%) | 616 (49%) | 1,108 (36%) | 21,466 (29%) | 24,215 (38%) |
| Grade 4 | 95 (5%) | 38 (3%) | 81 (3%) | 1,536 (2%) | 1,750 (2%) |
| Unknown | 410 (20%) | 169 (13%) | 965 (32%) | 5,425 (7%) | 6,969 (9%) |
| Estrogen receptor | |||||
| Estrogen receptor-positive | 862 (56%) | 653 (67%) | 1,533 (73%) | 49,960 (80%) | 53,008 (79%) |
| Estrogen receptor-negative | 675 (44%) | 319 (33%) | 573 (27%) | 12,419 (20%) | 13,986 (21%) |
| Missing | 477 | 296 | 953 | 11,379 | 13,105 |
| Progesterone receptor | |||||
| Progesterone receptor-positive | 666 (45%) | 511 (54%) | 1,123 (58%) | 40,555 (68%) | 42,855 (67%) |
| Progesterone receptor-negative | 819 (55%) | 430 (46%) | 826 (42%) | 19,137 (32%) | 21,212 (33%) |
| Missing | 529 | 327 | 1,110 | 14,066 | 16,032 |
| Hormone receptorb | |||||
| Hormone receptor-positive | 916 (60%) | 671 (69%) | 1,578 (75%) | 51,062 (82%) | 54,227 (81%) |
| Hormone receptor-negative | 626 (40%) | 303 (31%) | 533 (25%) | 11,499 (18%) | 12,961 (19%) |
| Missing | 472 | 294 | 948 | 11,197 | 12,911 |
| HER2 | |||||
| HER2-positive | 477 (40%) | 255 (35%) | 506 (35%) | 9,575 (22%) | 10,813 (23%) |
| HER2-negative | 703 (60%) | 484 (65%) | 942 (65%) | 34,754 (78%) | 36,883 (77%) |
| Missing | 834 | 529 | 1,611 | 29,429 | 32,403 |
| Surgical treatment | |||||
| None | 511 (25%) | 218 (17%) | 1,707 (56%) | 612 (<1%) | 3,048 (4%) |
| Mastectomy/lumpectomy/other | 1,500 (75%) | 1,050 (83%) | 1,352 (44%) | 73,145 (99%) | 77,047 (96%) |
| Unknown | 3 (0.2%) | 0 (0%) | 0 (0%) | 1 (0%) | 4 (0%) |
| Radiation therapy | |||||
| None | 1,022 (51%) | 779 (61%) | 2,041 (67%) | 37,334 (51%) | 41,176 (51%) |
| Any | 992 (49%) | 489 (39%) | 1,018 (33%) | 36,422 (49%) | 38,921 (49%) |
| Unknown | 0 (0%) | 0 (0%) | 0 (0%) | 2 (0%) | 2 (0%) |
| Chemotherapy | |||||
| None | 351 (17%) | 537 (42%) | 1,345 (44%) | 44,474 (60%) | 46,707 (58%) |
| Any | 1,625 (81%) | 683 (54%) | 1,606 (53%) | 27,428 (37%) | 31,342 (39%) |
| Unknown | 38 (2%) | 48 (4%) | 108 (4%) | 1,856 (3%) | 2,050 (3%) |
| Socioeconomic status | |||||
| Lowest | 358 (18%) | 235 (19%) | 509 (17%) | 7,786 (11%) | 8,888 (11%) |
| Second lowest | 379 (19%) | 263 (21%) | 584 (19%) | 11,900 (16%) | 13,126 (16%) |
| Middle | 427 (21%) | 265 (21%) | 631 (21%) | 15,376 (21%) | 16,699 (21%) |
| High | 465 (23%) | 252 (20%) | 705 (23%) | 17,608 (24%) | 19,030 (24%) |
| Highest | 385 (19%) | 253 (20%) | 630 (21%) | 21,088 (29%) | 22,356 (28%) |
aCalifornia Cancer Registry data, 1999 to 2004. P < 0.0001 for comparisons of each variable across the four major breast cancer subtypes. HER2, human epidermal growth factor-like receptor 2; SD, standard deviation. bHormone receptor-positive indicates estrogen receptor-positive and/or progesterone receptor-positive; hormone receptor-negative indicates estrogen receptor-negative and progesterone receptor-negative.