Table 2 Clinicopathologic characteristics of study patients in task 2
Characteristics | Training | P value | Validation | P value | Test | P value | |||
|---|---|---|---|---|---|---|---|---|---|
HER2-zero (n = 103) | HER2-low (n = 180) | HER2-zero (n = 34) | HER2-low (n = 88) | HER2-zero (n = 55) | HER2-low (n = 41) | ||||
Age | Â | Â | 0.13 | Â | Â | 1.00 | Â | Â | 0.24 |
 ≤ 40 | 16(15.53%) | 16(8.89%) |  | 6(17.65%) | 15(17.05%) |  | 5(9.09%) | 8(19.51%) |  |
 >40 | 87(84.47%) | 164(91.11%) |  | 28(82.35%) | 73(82.95%) |  | 50(90.91%) | 33(80.49%) |  |
Menopausal status | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Premenopausal | 51(49.51%) | 74(41.11%) | 0.21 | 12(35.29%) | 42(47.73%) | 0.30 | 29(52.73%) | 23(56.10%) | 0.90 |
 Postmenopausal | 52(50.49%) | 106(58.89%) |  | 22(64.71%) | 46(52.27%) |  | 26(47.27%) | 18(43.90%) |  |
Ki-67 | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 ≤ 20% (low) | 42(40.78%) | 102(56.67%) | 0.01 | 16(47.06%) | 62(70.45%) | 0.03 | 7(12.73%) | 8(19.51%) | 0.53 |
 >20% (high) | 61(59.22%) | 78(43.33%) |  | 18(52.94%) | 26(29.55%) |  | 48(87.27%) | 33(80.49%) |  |
Histomolecular class | Â | Â | Â | Â | Â | Â | Â | Â | Â |
 Luminal | 79(76.70%) | 160(88.89%) | 0.01 | 28(82.35%) | 83(94.32%) | 0.09 | 43(78.18%) | 39(95.12%) | <0.01 |
 Triple negative | 24(23.30%) | 20(11.11%) |  | 6(17.65%) | 5(5.68%) |  | 12(21.82%) | 2(4.88%) |  |
HR status | Â | Â | 0.02 | Â | Â | 0.09 | Â | Â | 0.01 |
 Negative | 24(23.30%) | 21(11.67%) |  | 6(17.65%) | 5(5.68%) |  | 12(21.82%) | 1(2.44%) |  |
 Positive | 79(76.70%) | 159(88.33%) |  | 28(82.35%) | 83(94.32%) |  | 43(78.18%) | 40(97.56%) |  |
LVI | Â | Â | 0.24 | Â | Â | 0.48 | Â | Â | 0.39 |
 Negative | 79(76.70%) | 125(69.44%) |  | 21(61.76%) | 62(70.45%) |  | 43(78.18%) | 28(68.29%) |  |
 Positive | 24(23.30%) | 55(30.56%) |  | 13(38.24%) | 26(29.55%) |  | 12(21.82%) | 13(31.71%) |  |
Clinical T stage | Â | Â | 0.26 | Â | Â | 0.01 | Â | Â | 0.16 |
 T1 | 58(56.31%) | 115(63.89%) |  | 15(44.12%) | 62(70.45%) |  | 32(58.18%) | 17(41.46%) |  |
 T2 or above | 45(43.69%) | 65(36.11%) |  | 19(55.88%) | 26(29.55%) |  | 23(41.82%) | 24(58.54%) |  |
Clinical N stage | Â | Â | 1.00 | Â | Â | 0.28 | Â | Â | 0.27 |
 N0 | 79(76.70%) | 138(76.67%) |  | 25(73.53%) | 74(84.09%) |  | 43(78.18%) | 27(65.85%) |  |
 N1+ | 24(23.30%) | 42(23.33%) |  | 9(26.47%) | 14(15.91%) |  | 12(21.82%) | 14(34.15%) |  |
Histology type | Â | Â | 1.00 | Â | Â | 1.00 | Â | Â | 0.16 |
 IBC-NST | 90(87.38%) | 158(87.78%) |  | 29(85.29%) | 76(86.36%) |  | 54(98.18%) | 37(90.24%) |  |
 ILC or others | 13(12.62%) | 22(12.22%) |  | 5(14.71%) | 12(13.64%) |  | 1(1.82%) | 4(9.76%) |  |
Grade | Â | Â | 0.09 | Â | Â | 0.20 | Â | Â | 0.15 |
 I or II | 61(59.22%) | 126(70.00%) |  | 23(67.65%) | 71(80.68%) |  | 27(49.09%) | 27(65.85%) |  |
 III | 42(40.78%) | 54(30.00%) |  | 11(32.35%) | 17(19.32%) |  | 28(50.91%) | 14(34.15%) |  |