Table 1.
Demographic and clinical characteristics of patients with ≥1 tumor assessments before and after nIPTW
| Before nIPTW | After nIPTW | |||||
|---|---|---|---|---|---|---|
| Characteristica,b | Palbociclib + AI (n = 103)c |
AI monotherapy (n = 71)c |
Standardized mean differenced | Palbociclib + AI (n = 103) |
AI monotherapy (n = 71) |
Standardized mean differenced |
| Age, years | ||||||
| < 30 | 0 | 0 | 0 | 0 | ||
| 30−44 | 41 (39.8) | 29 (40.8) | 0.0212 | 44 (42.7) | 29 (40.8) | − 0.0496 |
| ≥ 45 | 62 (60.2) | 42 (59.2) | − 0.0212 | 59 (57.3) | 42 (59.2) | 0.0496 |
| Mean (SD) | 45.8 (6.4) | 46.1 (7.2) | 0.0428 | 45.9 (6.6) | 45.8 (6.8) | − 0.0038 |
| Median (min, max) | 46.0 (31.0, 58.0) | 46.0 (30.0, 60.0) | 46.0 (31.0, 58.0) | 46.0 (30.0, 60.0) | ||
| Race | ||||||
| Black | 12 (11.7) | 9 (12.7) | 0.0314 | 12 (11.7) | 9 (12.7) | 0.0527 |
| White | 68 (66.0) | 48 (67.6) | 0.0337 | 68 (66.0) | 46 (64.8) | − 0.0044 |
| Not reported/unknown | 23 (22.3) | 14 (19.7) | − 0.0641 | 23 (22.3) | 15 (21.1) | − 0.0370 |
| Weight, kg | ||||||
| n | 96 | 61 | 96 | 61 | ||
| Mean (SD) | 75.9 (17.7) | 74.6 (18.3) | − 0.0704 | 76.0 (17.3) | 74.0 (19.1) | − 0.1106 |
| Median (min, max) | 72.8 (47.8, 129.3) | 72.6 (44.7, 131.1) | 72.8 (47.8, 129.3) | 72.6 (44.7, 131.1) | ||
| BMI, kg/m2 | ||||||
| n | 96 | 61 | 96 | 61 | ||
| Mean (SD) | 28.2 (6.3) | 28.0 (6.5) | − 0.0326 | 28.1 (6.3) | 27.7 (6.8) | − 0.0611 |
| Median (min, max) | 27.3 (16.1, 46.0) | 26.2 (16.0, 51.2) | 27.3 (16.1, 46.0) | 26.2 (16.0, 51.2) | ||
| BMI ≥ 25 kg/m2 | ||||||
| Yes | 68 (66.0) | 37 (52.1) | − 0.2857 | 64 (62.1) | 40 (56.3) | − 0.1106 |
| No | 28 (27.2) | 24 (33.8) | 0.1441 | 30 (29.1) | 24 (33.8) | 0.0912 |
| Unknown | 7 (6.8) | 10 (14.1) | 0.2401 | 9 (8.7) | 7 (9.9) | 0.0409 |
| Tobacco use | ||||||
| No history of tobacco use | 69 (67.0) | 36 (50.7) | − 0.3356 | 71 (68.9) | 37 (52.1) | − 0.3350 |
| Current tobacco use | 7 (6.8) | 10 (14.1) | 0.2401 | 7 (6.8) | 9 (12.7) | 0.2103 |
| Prior tobacco use | 24 (23.3) | 11 (15.5) | − 0.1984 | 23 (22.3) | 11 (15.5) | − 0.1819 |
| Unknown | 3 (2.9) | 14 (19.7) | 0.5502 | 2 (1.9) | 14 (19.7) | 0.5673 |
| Family history of cancer | ||||||
| Yes | 69 (67.0) | 49 (69.0) | 0.0434 | 66 (64.1) | 49 (69.0) | 0.1071 |
| No | 34 (33.0) | 22 (31.0) | − 0.0434 | 37 (35.9) | 22 (31.0) | − 0.1071 |
| Hormone receptor status | ||||||
| ER+ only | 16 (15.5) | 12 (16.9) | 0.0371 | 17 (16.5) | 13 (18.3) | 0.0365 |
| PR+ only | 1 (1.0) | 0 | − 0.1400 | 1 (1.0) | 0 | − 0.1358 |
| ER+ and PR+ | 86 (83.5) | 59 (83.1) | − 0.0106 | 85 (82.5) | 58 (81.7) | − 0.0122 |
| Stage at diagnosis | ||||||
| Stage 0 or I | 21 (20.4) | 9 (12.7) | − 0.2087 | 18 (17.5) | 12 (16.9) | − 0.0223 |
| Stage II | 36 (35.0) | 25 (35.2) | 0.0054 | 35 (34.0) | 26 (36.6) | 0.0381 |
| Stage III | 17 (16.5) | 16 (22.5) | 0.1526 | 22 (21.4) | 14 (19.7) | − 0.0317 |
| Stage IV | 26 (25.2) | 18 (25.4) | 0.0025 | 24 (23.3) | 17 (23.9) | 0.0014 |
| Unknown | 3 (2.9) | 3 (4.2) | 0.0708 | 3 (2.9) | 2 (2.8) | 0.0137 |
| Disease histology | ||||||
| Ductal | 71 (68.9) | 55 (77.5) | 0.1935 | 72 (69.9) | 58 (81.7) | 0.2605 |
| Lobular | 12 (11.7) | 6 (8.5) | − 0.1066 | 13 (12.6) | 5 (7.0) | − 0.1686 |
| Mixed | 5 (4.9) | 5 (7.0) | 0.0926 | 4 (3.9) | 4 (5.6) | 0.0945 |
| Metaplastic | 0 | 0 | 0 | 0 | ||
| Mucinous | 1 (1.0) | 0 | − 0.1400 | 1 (1.0) | 0 | − 0.1150 |
| Other | 1 (1.0) | 0 | − 0.1400 | 1 (1.0) | 0 | − 0.1361 |
| Unknown | 13 (12.6) | 5 (7.0) | − 0.1882 | 12 (11.7) | 4 (5.6) | − 0.2283 |
| Prior neo/adjuvant chemotherapy | ||||||
| Yes | 43 (41.7) | 32 (45.1) | 0.0671 | 46 (44.7) | 29 (40.8) | − 0.0657 |
| No | 60 (58.3) | 39 (54.9) | − 0.0671 | 57 (55.3) | 42 (59.2) | 0.0657 |
| Prior neo/adjuvant endocrine therapy | ||||||
| Yes | 51 (49.5) | 43 (60.6) | 0.2235 | 50 (48.5) | 41 (57.7) | 0.1870 |
| No | 52 (50.5) | 28 (39.4) | − 0.2235 | 53 (51.5) | 30 (42.3) | − 0.1870 |
| ECOG PS score | ||||||
| 0 | 33 (32.0) | 24 (33.8) | 0.0375 | 33 (32.0) | 23 (32.4) | 0.0021 |
| 1 | 36 (35.0) | 22 (31.0) | − 0.0844 | 33 (32.0) | 22 (31.0) | − 0.0225 |
| ≥ 2 | 7 (6.8) | 7 (9.9) | 0.1110 | 10 (9.7) | 7 (9.9) | 0.0320 |
| Unknown | 27 (26.2) | 18 (25.4) | − 0.0197 | 27 (26.2) | 18 (25.4) | 0.0000 |
| CCI score | ||||||
| 0 | 84 (81.6) | 62 (87.3) | 0.1597 | 85 (82.5) | 63 (88.7) | 0.1997 |
| 1 | 12 (11.7) | 3 (4.2) | − 0.2773 | 12 (11.7) | 2 (2.8) | − 0.3393 |
| 2 | 4 (3.9) | 4 (5.6) | 0.0823 | 3 (2.9) | 4 (5.6) | 0.1377 |
| 3 | 3 (2.9) | 0 | − 0.2449 | 3 (2.9) | 0 | − 0.2424 |
| 4 | 0 | 1 (1.4) | 0.1690 | 0 | 1 (1.4) | 0.1479 |
| 6 | 0 | 1 (1.4) | 0.1690 | 0 | 1 (1.4) | 0.1269 |
| Metastatic disease site | ||||||
| Viscerale | 33 (32.0) | 23 (32.4) | 0.0076 | 32 (31.1) | 23 (32.4) | 0.0127 |
| Non-visceral | 40 (38.8) | 17 (23.9) | − 0.3251 | 32 (31.1) | 21 (29.6) | − 0.0308 |
| Bone onlyf | 30 (29.1) | 31 (43.7) | 0.3056 | 38 (36.9) | 27 (38.0) | 0.0172 |
| Number of metastatic sites | ||||||
| 1 | 28 (27.2) | 28 (39.4) | 0.2622 | 35 (34.0) | 26 (36.6) | 0.0513 |
| 2 | 39 (37.9) | 18 (25.4) | − 0.2716 | 32 (31.1) | 21 (29.6) | − 0.0238 |
| ≥ 3 | 36 (35.0) | 25 (35.2) | 0.0054 | 36 (35.0) | 24 (33.8) | − 0.0283 |
| Disease-free interval | ||||||
| < 12 months | 48 (46.6) | 29 (40.8) | − 0.1163 | 44 (42.7) | 30 (42.3) | − 0.0124 |
| ≥ 12 months | 13 (12.6) | 16 (22.5) | 0.2627 | 20 (19.4) | 13 (18.3) | − 0.0511 |
| De novo metastatic | 30 (29.1) | 19 (26.8) | − 0.0527 | 27 (26.2) | 18 (25.4) | − 0.0066 |
| Unknown | 12 (11.7) | 7 (9.9) | − 0.0578 | 11 (10.7) | 10 (14.1) | 0.0879 |
AI aromatase inhibitor, BMI body mass index, CCI Charlson Comorbidity Index, ECOG PS Eastern Cooperative Oncology Group performance status, ER estrogen receptor, max maximum, min minimum, nIPTW normalized inverse probability treatment weighting, PR progesterone receptor, SD standard deviation
aAll data are listed as n (%) unless otherwise indicated
bCharacteristics in bold were used for propensity scoring and subsequent nIPTW
cn values apply to each characteristic unless a different n value is provided
dStandardized mean differences < 0.1 were considered indicative of acceptable balance
eVisceral includes liver, lung, and pleura
fBone only includes bone, bone marrow, pelvis, ribs, skull, and spine