Table 2 Degree of pathological response in subgroups based on HER2 targeted therapy and oestrogen receptor status.
Variables | HER2 IHC defined groups | Total No. (%) | p-value | Adjusted p value (Bonferroni correction) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
IHC 2+ Group | IHC 3+ Group | IHC0/1+ Group | ||||||||
Group 1 No. (%) | Group 2 No. (%) | Group 3 No. (%) | Group 4 No. (%) | Group 5 No. (%) | Positive control No. (%) | Negative control No. (%) | ||||
Whole cohort | ||||||||||
HER2 Targeted therapy not offered | ||||||||||
No response | 2 (15) | 0 (0) | 0 (0) | 5 (6) | 17 (16) | 1 (13) | 37 (16) | 62 (14) | 0.003 | 0.009 |
Partial response | 10 (77) | 4 (80) | 5 (100) | 70 (83) | 77 (73) | 5 (63) | 147 (63) | 318 (70) | ||
Pathological complete response | 1 (8) | 1 (20) | 0 (0) | 9 (11) | 12 (11) | 2 (24) | 49 (21) | 74 (16) | ||
HER2 Targeted therapy given | ||||||||||
No response | 3 (3) | 2 (5) | 0 (0) | 0 (0) | 0 (0) | 9 (6) | 0 (0) | 14 (5) | <0.0001 | <0.0001 |
Partial response | 84 (78) | 28 (68) | 7 (88) | 0 (0) | 0 (0) | 52 (38) | 0 (0) | 171 (58) | ||
Pathological complete response | 21 (19) | 11 (27) | 1 (12) | 0 (0) | 0 (0) | 77 (56) | 0 (0) | 110 (37) | ||
Oestrogen receptor negative | ||||||||||
No response | 1 (4) | 0 (0) | 0 (0) | 2 (12) | 3 (11) | 4 (6) | 21 (19) | 31 (12) | 0.030 | 0.054 |
Partial response | 15 (58) | 7 (58) | 0 (0) | 11 (69) | 16 (62) | 26 (41) | 58 (51) | 131 (52) | ||
Pathological complete response | 10 (38) | 5 (42) | 0 (0) | 3 (19) | 7 (27) | 34 (53) | 34 (30) | 93 (36) | ||
Oestrogen receptor positive | ||||||||||
No response | 4 (4) | 2 (6) | 0 (0) | 3 (4) | 14 (18) | 6 (7) | 16 (14) | 45 (9) | <0.0001 | <0.0001 |
Partial response | 79 (83) | 25 (73) | 12 (92) | 59 (87) | 61 (76) | 30 (37) | 87 (74) | 353 (72) | ||
Pathological complete response | 12 (13) | 7 (21) | 1 (8) | 6 (9) | 5 (6) | 45 (56) | 15 (13) | 91 (19) | ||
HER2 targeted therapy treated cohort | ||||||||||
Oestrogen receptor negative | ||||||||||
No response | 1 (4) | 0 (0) | 0 (0) | – | – | 3 (5) | – | 4 (4) | ||
Partial response | 13 (57) | 7 (63) | 0 (0) | – | – | 25 (42) | – | 45 (48) | 0.281 | 0.680 |
Pathological complete response | 9 (39) | 4 (37) | 0 (0) | – | – | 32 (53) | – | 45 (48) | ||
Oestrogen receptor positive | ||||||||||
No response | 2 (2) | 2 (7) | 0 (0) | – | – | 6 (8) | – | 10 (5) | <0.0001 | <0.0001 |
Partial response | 71 (84) | 22 (73) | 7 (87) | – | – | 26 (34) | – | 126 (63) | ||
Pathological complete response | 12 (14) | 6 (20) | 1 (13) | – | – | 45 (58) | – | 64 (32) | ||
