Table 1:
Demographics, baseline characteristics, and previous systemic therapies in the intention-to-treat population
| Abemaciclib plus endocrine therapy group (n=2808)* | Endocrine therapy alone group (n=2829)* | |
|---|---|---|
| Age, median (IQR), years | 51 (44–60) | 51 (44–60) |
| <65 | 2371 (84·4%) | 2416 (85·4%) |
| ≥65 | 437 (15.6%) | 413 (14·6%) |
| Sex | ||
| Female | 2787 (99·3%) | 2814 (99·5%) |
| Male | 21 (0·7%) | 15 (0·5%) |
| Hormone receptor status | ||
| Oestrogen receptor positive | 2786 (99·2%) | 2810 (99·3%) |
| Oestrogen receptor negative | 16 (0·6%) | 17 (0·6%) |
| Progesterone receptor positive | 2426 (86·4%) | 2456 (86·8%) |
| Progesterone receptor negative | 298 (10·6%) | 295 (10·4%) |
| Menopausal status†‡ | ||
| Premenopausal | 1221 (43·5%) | 1232 (43·5%) |
| Postmenopausal | 1587 (56·5%) | 1597 (56·5%) |
| Region† | ||
| North American or Europe | 1470 (52·4%) | 1479 (52·3%) |
| Asia | 574 (20·4%) | 582 (20·6%) |
| Other | 764 (27·2%) | 768 (27·1%) |
| Race | ||
| American Indian or Alaska Native | 64 (2·3%) | 58 (2·1%) |
| Asian | 675 (24·0%) | 669 (23·6%) |
| Black or African American | 57 (2·0%) | 53 (1·9%) |
| Native Hawaiian or other Pacific Islander | 3 (0·1%) | 4 (0·1%) |
| White | 1947 (69·3%) | 1978 (69·9%) |
| Multiple | 22 (0·8%) | 25 (0·9%) |
| Ethnicity (reported in the USA only)§ | ||
| Hispanic or Latinx | 33 (8·3%) | 36 (8·7%) |
| Not Hispanic or Latinx | 364 (91·7%) | 377 (91·3%) |
| Positive axillary lymph nodes | ||
| 0 | 7 (0·2%) | 7 (0·2%) |
| 1–3 | 1118 (39·8%) | 1142 (40·4%) |
| ≥4 | 1682 (59·9%) | 1680 (59·4%) |
| Histopathological grade at diagnosis | ||
| Grade 1 | 209 (7·4%) | 216 (7·6%) |
| Grade 2 | 1377 (49·0%) | 1395 (49·3%) |
| Grade 3 | 1086 (38·7%) | 1064 (37·6%) |
| Not assessable | 126 (4·5%) | 141 (5·0%) |
| Pathological tumour size, cm | ||
| <2 | 781 (27·8%) | 767 (27·1%) |
| 2–5 | 1372 (48·9%) | 1419 (50·2%) |
| ≥5 | 607 (21·6%) | 610 (21·6%) |
| Ki-67 index | ||
| <20% | 953 (33·9%) | 974 (34·4%) |
| ≥20% | 1262 (44·9%) | 1233 (43·6%) |
| Tumour, node, metastasis stage¶ | ||
| IA | 2 (0·1%) | 1 (0·0%) |
| IIA | 324 (11·5%) | 353 (12·5%) |
| IIB | 392 (14·0%) | 387 (13·7%) |
| IIIA | 1029 (36·6%) | 1026 (36·3%) |
| IIIB | 99 (3·5%) | 88 (3·1%) |
| IIIC | 950 (33·8%) | 963 (34·0%) |
| Previous therapies for breast cancer | ||
| Previous chemotherapy | ||
| Neoadjuvant chemotherapy | 1026 (36·5%) | 1029 (36·4%) |
| Adjuvant chemotherapy | 1734 (61·8%) | 1731 (61·2%) |
| Previous endocrine therapy | ||
| Neoadjuvant endocrine therapy | 86 (3·1%) | 97 (3·4%) |
| Adjuvant endocrine therapy | 1764 (62·8%) | 1795 (63·4%) |
| Median time from start of endocrine therapy to randomisation, weeks | 7·6 (3·7–11·0) | 7·9 (3·9–11·3) |
| Previous radiotherapy | ||
| Neoadjuvant radiotherapy | 71 (2·5%) | 82 (2·9%) |
| Adjuvant radiotherapy | 2620 (93·3%) | 2628 (92·9%) |
| Surgical procedure with curative intent | 2804║ (99·9%) | 2829 (100·0%) |
| Median time from surgery to randomisation, months | 7·8 (4·7–9·6) | 7·9 (4·7–9·6) |
Data are n (%) or median (IQR).
*
Where values do not add up to 100%, remaining data are missing, unavailable, or could not be assessed.
†
Per interactive web response system.
‡
Menopausal status is at the time of diagnosis and all male patients are considered postmenopausal.
§
397 patients in the abemaciclib plus endocrine therapy group and 413 in the endocrine therapy alone group.
¶
Derived tumour, node, metastasis stage based on the pathological tumour size and number of positive lymph nodes following primary surgery.
║
Four patients who did not have definitive surgery in the breast were enrolled in the study without meeting eligibility criteria.