Table A3.
Demographic and disease characteristics on the index date a in the primary cohort b stratified by prior pertuzumab use.
| Pertuzumab-Naive (n = 295) |
Pertuzumab-Experienced (n = 462) | ||||||
|---|---|---|---|---|---|---|---|
| 2013–2014 (n = 48) |
2015–2016 (n = 131) |
2017–2018 (n = 167) |
2019 (n = 116) |
Overall (n = 462) |
p-Value | ||
| Median age, years (IQR) | 65 (55–74) | 58 (51–67) | 59 (51–67) | 61 (51–70) | 61 (53–69) | 60 (52–69) | 0.279 |
| Median BMI, kg/m2 (IQR) | 28 (24–32) | 28 (24–33) | 27 (24–34) | 29 (24–33) | 28 (23–33) | 28 (23–33) | 0.849 |
| Practice setting, n (%) | 0.498 | ||||||
| Academic | 18 (6) | 6 (12) | 15 (11) | 14 (8) | 8 (7) | 43 (9) | |
| Community based | 277 (94) | 42 (88) | 116 (89) | 153 (92) | 108 (93) | 419 (91) | |
| Metastatic status, n (%) | 0.055 | ||||||
| De novo | 87 (29) | 20 (42) | 51 (39) | 89 (53) | 60 (52) | 220 (48) | |
| Recurrent | 208 (71) | 28 (58) | 80 (61) | 78 (47) | 56 (48) | 242 (52) | |
| Median number of metastatic sites, n (IQR) | 2 (1–4) | 3 (2–4) | 3 (2–4) | 3 (2–4) | 3 (2–4) | 3 (2–4) | 0.780 |
| Metastatic site, n (%) | |||||||
| Visceral | 172 (58) | 37 (77) | 106 (81) | 122 (73) | 83 (72) | 348 (75) | 0.304 |
| Bone | 163 (55) | 29 (60) | 76 (58) | 111 (66) | 75 (65) | 291 (63) | 0.470 |
| Distant lymph node | 135 (46) | 21 (44) | 60 (46) | 91 (54) | 50 (43) | 222 (48) | 0.209 |
| Lung | 115 (39) | 20 (42) | 64 (49) | 74 (44) | 54 (47) | 212 (46) | 0.802 |
| Liver | 100 (34) | 26 (54) | 62 (47) | 83 (50) | 51 (44) | 222 (48) | 0.636 |
| Brain | 49 (17) | 10 (21) | 37 (28) | 41 (25) | 32 (28) | 120 (26) | 0.719 |
| Non-brain CNS | 8 (3) | ≤5 (<11) | ≤5 (<4) | 7 (4) | ≤5 (<5) | 20 (4) | 0.501 |
| Other | 11 (4) | ≤5 (<11) | 7 (5) | 9 (5) | 8 (7) | 24 (5) | 0.327 |
| Hormone receptor status, n (%) | 0.678 | ||||||
| Positive | 207 (70) | 33 (69) | 99 (76) | 129 (77) | 86 (74) | 347 (8) | |
| Negative | 85 (29) | 15 (31) | 32 (24) | 38 (23) | 30 (26) | 115 (25) | |
| Unknown | ≤5 (<2) | ≤5 (<11) | ≤5 (<4) | ≤5 (<3) | ≤5 (<5) | ≤5 (<2) | |
| Approximate number of prior lines of therapy, n (%) | 0.381 c | ||||||
| 0 | 104 (35) | <4 (<9) | <4 (<4) | <4 (<3) | <4 (<4) | <4 (<1) | |
| 1 | 88 (30) | 28 (58) | 71 (54) | 82 (49) | 67 (58) | 248 (54) | |
| 2 | 60 (20) | 9 (19) | 36 (27) | 55 (33) | 22 (19) | 122 (26) | |
| 3 | 20 (7) | 8 (17) | 12 (9) | 13 (8) | 20 (17) | 53 (11) | |
| 4 | 10 (3) | ≤5 (<11) | ≤5 (<4) | 6 (4) | ≤5 (<5) | 16 (3) | |
| ≥5 | 13 (4) | ≤5 (<11) | 8 (6) | 11 (7) | ≤5 (<5) | 22 (5) | |
| Mean time from mBC diagnosis to T-DM1 initiation, months (SD) | 14.2 (15.4) | 13.6 (7.6) | 16.6 (11.3) | 21.5 (13.3) | 24.9 (17.4) | 20.1 (14.0) | <0.001 |
a Date on or prior to 31 December 2019, that treatment with T-DM1 was initiated. b Patients who received T-DM1 in any treatment line. c Due to sample size, the comparison is between 0–1 vs. 2 prior lines of therapy. BMI = body mass index; CNS = central nervous system; IQR = interquartile range; mBC = metastatic breast cancer; SD = standard deviation; T-DM1 = trastuzumab emtansine.