TABLE 1.
Distribution of Demographic, Clinical, and Treatment Characteristics of Patients in NSABP B-42 According to Inclusion in the Translational MP Cohort
| Characteristic | Translational MP Cohort | P a | Translational MP Cohort (n = 1,866) | Excluded B-42 Cohort (n = 2,037) | P b | Overall B-42 Population (N = 3,903) | |
|---|---|---|---|---|---|---|---|
| Placebo (n = 950) | Letrozole (n = 916) | ||||||
| No. (%) | No. (%) | No. (%) | No. (%) | No. (%) | |||
| Age at random assignment, yrs | |||||||
| <60 | 306 (32.2) | 317 (34.6) | .27 | 623 (33.4) | 721 (35.4) | .19 | 1,344 (34.4) |
| ≥60 | 644 (67.8) | 599 (65.4) | 1,243 (66.6) | 1,316 (64.6) | 2,559 (65.6) | ||
| Pathologic nodal status | |||||||
| Negative | 547 (57.6) | 506 (55.2) | .31 | 1,053 (56.4) | 1,187 (58.3) | .25 | 2,240 (57.4) |
| Positive | 403 (42.4) | 410 (44.8) | 813 (43.6) | 850 (41.7) | 1,663 (42.6) | ||
| Lowest BMD T-score | |||||||
| ≤–2.0 | 237 (24.9) | 232 (25.3) | .85 | 469 (25.1) | 485 (23.8) | .34 | 954 (24.4) |
| >–2.0 | 713 (75.1) | 684 (74.7) | 1,397 (74.9) | 1,552 (76.2) | 2,949 (75.6) | ||
| Received prior tamoxifen | |||||||
| No | 581 (61.2) | 559 (61.0) | .95 | 1,140 (61.1) | 1,237 (60.7) | .81 | 2,377 (60.9) |
| Yes | 369 (38.8) | 357 (39.0) | 726 (38.9) | 800 (39.3) | 1,526 (39.1) | ||
| HER2 status | |||||||
| Negative | 742 (78.1) | 737 (80.5) | .15 | 1,479 (79.3) | 1,562 (76.7) | .04 | 3,041 (77.9) |
| Positive | 134 (14.1) | 128 (14.0) | 262 (14.0) | 297 (14.6) | 559 (14.3) | ||
| Not done/unknown | 74 (7.8) | 51 (5.6) | 125 (6.7) | 178 (8.7) | 303 (7.8) | ||
| Surgery type | |||||||
| Lumpectomy | 583 (61.4) | 538 (58.7) | .25 | 1,121 (60.1) | 1,253 (61.5) | .36 | 2,374 (60.8) |
| Mastectomy | 367 (38.6) | 378 (41.3) | 745 (39.9) | 784 (38.5) | 1,529 (39.2) | ||
| Treatment | |||||||
| Placebo | 950 (50.9) | 1,003 (49.2) | .30 | 1,953 (50.0) | |||
| Letrozole | 916 (49.1) | 1,034 (50.8) | 1,950 (50.0) | ||||
Abbreviations: BMD, bone mineral density; HER2, human epidermal growth factor receptor 2; MP, MammaPrint.
a
Comparison between placebo and letrozole.
b
Comparison between the translational MP cohort and excluded B-42 population.