Table 1 Patient demographic characteristics according to regimen after T-DM1
All (N = 128) | Regimen after T-DM1 | ||
|---|---|---|---|
Anti-HER2 therapy (n = 105) | Without anti-HER2 therapy (n = 23) | ||
Age (years) | |||
Median (range) | 59.0 (27–84) | 60.0 (36–84) | 57.0 (27–78) |
≥ 60 years | 62 (48.4) | 54 (51.4) | 8 (34.8) |
ECOG PS | |||
0 | 67 (52.3) | 57 (54.3) | 10 (43.5) |
1 | 25 (19.5) | 20 (19.0) | 5 (21.7) |
≥ 2 | 9 (7.0) | 6 (5.7) | 3 (13.0) |
Unknown | 27 (21.1) | 22 (21.0) | 5 (21.7) |
Hormone receptor status | |||
Positive | 83 (64.8) | 66 (62.9) | 17 (73.9) |
Negative | 43 (33.6) | 38 (36.2) | 5 (21.7) |
Unknown | 2 (1.6) | 1 (1.0) | 1 (4.3) |
HER2 status | |||
IHC3+ | 104 (81.3) | 83 (79.0) | 21 (91.3) |
IHC2+ and ISH+ | 21 (16.4) | 19 (18.1) | 2 (8.7) |
IHC not performed and ISH + a | 3 (2.3) | 3 (2.9) | 0 (0.0) |
Type of metastatic breast cancer | |||
De novob | 46 (35.9) | 39 (37.1) | 7 (30.4) |
Recurrent | 82 (64.1) | 66 (62.9) | 16 (69.6) |
Disease-free interval (months), median (range)c | 39.59 (7.9–198.3) | 39.59 (7.9–198.3) | 42.00 (9.9–193.8) |
Metastatic stie at initial metastatic diagnosis | |||
Liver | 42 (32.8) | 34 (32.4) | 8 (34.8) |
Lung | 36 (28.1) | 33 (31.4) | 3 (13.0) |
Bone | 44 (34.4) | 37 (35.2) | 7 (30.4) |
Peritoneal dissemination | 7 (5.5) | 6 (5.7) | 1 (4.3) |
Ascites | 0 (0.0) | 0 (0.0) | 0 (0.0) |
CNS | 5 (3.9) | 5 (4.8) | 0 (0.0) |
Skin/subcutaneous soft tissues | 17 (13.3) | 14 (13.3) | 3 (13.0) |
Lymph nodes | 60 (46.9) | 50 (47.6) | 10 (43.5) |
Others | 6 (4.7) | 5 (4.8) | 1 (4.3) |
Drug therapy prior to T-DM1 treatment | |||
Anti-HER2 therapy | |||
Trastuzumab | 120 (93.8) | 99 (94.3) | 21 (91.3) |
Pertuzumab | 72 (56.3) | 58 (55.2) | 14 (60.9) |
Lapatinib | 36 (28.1) | 28 (26.7) | 8 (34.8) |
None | 6 (4.7) | 5 (4.8) | 1 (4.3) |
Chemotherapy | |||
Anthracycline-based | 64 (50.0) | 50 (47.6) | 14 (60.9) |
Taxane-based | 108 (84.4) | 88 (83.8) | 20 (87.0) |
Paclitaxel | 56 (43.8) | 42 (40.0) | 14 (60.9) |
Docetaxel | 80 (62.5) | 67 (63.8) | 13 (56.5) |
Neither anthracycline nor taxane | 19 (14.8) | 16 (15.2) | 3 (13.0) |
Capecitabine/S-1 | 47 (36.7) | 34 (32.4) | 13 (56.5) |
No. of chemotherapy treatments before T-DM1 in any setting | |||
0 | 13 (10.2) | 11 (10.5) | 2 (8.7) |
1 | 36 (28.1) | 32 (30.5) | 4 (17.4) |
2 | 25 (19.5) | 21 (20.0) | 4 (17.4) |
≥ 3 | 54 (42.2) | 41 (39.0) | 13 (56.5) |
Duration from initial metastatic diagnosis to the start of T-DM1 treatment (months) | |||
Median (range) | 22.00 (0.03–174.9) | – | – |
Best response with T-DM1 | |||
CR, PR | 46 (35.9) | 42 (40.0) | 4 (17.4) |
SD, non-CR/non-PD, PD | 80 (62.5) | 62 (59.0) | 18 (78.3) |
Unknown | 2 (1.6) | 1 (1.0) | 1 (4.3) |
Duration of T-DM1 treatment (months) | |||
Median (range) | 5.09 (0.03–41.4) | 5.78 (0.7–41.4) | 2.33 (0.03–26.5) |
< 6 months | 74 (57.8) | 54 (51.4) | 20 (87.0) |
≥ 6 to < 12 months | 30 (23.4) | 29 (27.6) | 1 (4.3) |
≥ 12 months | 24 (18.8) | 22 (21.0) | 2 (8.7) |
Reason for T-DM1 treatment discontinuation | |||
Disease progression | 102 (79.7) | 82 (78.1) | 20 (87.0) |
Toxicity | 21 (16.4) | 19 (18.1) | 2 (8.7) |
Other | 5 (3.9) | 4 (3.8) | 1 (4.3) |
Metastatic site at start of drug therapy after T-DM1 treatment discontinuation | |||
Viscera | 89 (69.5) | 72 (68.6) | 17 (73.9) |
Skin/subcutaneous soft tissues/lymph nodes | 76 (59.4) | 64 (61.0) | 12 (52.2) |
Bone | 53 (41.4) | 42 (40.0) | 11 (47.8) |
CNS | 17 (13.3) | 15 (14.3) | 2 (8.7) |
Other | 9 (7.0) | 8 (7.6) | 1 (4.3) |