Table 1 Baseline characteristics in training and validation sets
Variable | Training set | Internal validation set | P Value | External validation set | P Value |
|---|---|---|---|---|---|
Number of lesions | 181 | 54 | Â | 65 | Â |
Median age (year) | 47(41–55)a | 48(40–61)a | 0.55 | 47(41–63)a | 0.38 |
Median size (cm) | 1.3(0.9–2.1)a | 1.1(0.9–1.8)a | 0.27 | 1.4(0.9–1.4)a | 0.97 |
Nipple discharge | Â | Â | 0.35 | Â | 0.73 |
 Absent | 144(79.6) | 46(85.2) |  | 53(81.5) |  |
 Present | 37(20.4) | 8(14.8) |  | 12(18.5) |  |
Palpability | Â | Â | 0.17 | Â | 0.29 |
 Impalpable | 54(29.8) | 11(20.4) |  | 24(36.9) |  |
 Palpable | 127(70.2) | 43(79.6) |  | 41(63.1) |  |
Biopsy needle |  |  | < 0.001 |  | 0.001 |
 14-Gauge | 0 | 0 |  | 43(66.2) |  |
 16-Gauge | 105(58.0) | 13(24.1) |  | 22(33.8) |  |
 18-Gauge | 76(42.0) | 41(75.9) |  | 0 |  |
Number of cores | Â | Â | 0.01 | Â | 0.98 |
 2 | 58(32.0) | 6(11.1) |  | 20(30.8) |  |
 3 | 107(59.2) | 42(77.8) |  | 39(60.0) |  |
 4–6 | 16(8.8) | 6(11.1) |  | 6(9.2) |  |
Distance from nipple | Â | Â | 0.57 | Â | 0.31 |
 ≤ 2 cm | 105(58.0) | 29(53.7) |  | 33(50.8) |  |
 > 2 cm | 76(42.0) | 25(46.3) |  | 32(49.2) |  |
Pathological pattern | Â | Â | 0.22 | Â | 0.40 |
 With fibroadenoma | 12(6.6) | 2(3.7) |  | 7(10.8) |  |
 With adenosis | 46(25.4) | 8(14.8) |  | 12(18.4) |  |
 With intraductal papilloma | 60(33.0) | 18(33.3) |  | 26(40.0) |  |
 ADH alone | 63(34.8) | 26(48.2) |  | 20(30.8) |  |
ER status(n = 287) |  |  | 0.34 |  | 0.33 |
 Negative | 22(12.6) | 4(7.8) |  | 5(8.1) |  |
 Positive | 152(87.4) | 47(92.2) |  | 57(91.9) |  |
PR status(n = 287) |  |  | 0.97 |  | 0.25 |
 Negative | 27(15.5) | 8(15.7) |  | 6(9.7) |  |
 Positive | 147(84.5) | 43(84.3) |  | 56(90.3) |  |
Ki-67 status(n = 250) |  |  | 0.95 |  | 0.44 |
 Negative | 105(71.9) | 34(72.3) |  | 44(77.2) |  |
 Positive | 41(28.1) | 13(27.7) |  | 13(22.8) |  |
Negative edge of core | Â | Â | 0.69 | Â | 0.60 |
 Yes | 86(47.5) | 24(44.4) |  | 28(43.8) |  |
 No | 95(52.5) | 30(55.6) |  | 36(56.2) |  |
Max extent of ADH foci | Â | Â | 0.38 | Â | 0.74 |
 ≤ 0.1 cm | 75(41.4) | 26(48.1) |  | 28(43.8) |  |
 > 0.1 cm | 106(58.6) | 28(51.9) |  | 36(56.2) |  |
ADH foci number | Â | Â | 0.006 | Â | 0.18 |
 ≤ 2 | 57(31.5) | 28(51.9) |  | 26(40.6) |  |
 >2 | 124(68.5) | 26(48.1) |  | 38(59.4) |  |
Lesion types | Â | Â | 0.59 | Â | 0.80 |
 Mass-like lesion | 145(80.1) | 45(83.3) |  | 53(81.5) |  |
 Non-mass-like lesion | 36(19.9) | 9(16.7) |  | 12(18.5) |  |
Shape | Â | Â | 0.60 | Â | 0.76 |
 Round/Oval | 25(13.8) | 9(16.7) |  | 8(12.3) |  |
 Irregular | 156(86.2) | 45(83.3) |  | 57(87.7) |  |
Margin | Â | Â | 0.42 | Â | 0.41 |
 Circumscribed | 63(34.8) | 22(40.7) |  | 19(29.2) |  |
 Not circumscribed | 118(65.2) | 32(59.3) |  | 46(70.8) |  |
Composition | Â | Â | 0.89 | Â | 0.46 |
 Solid | 175(96.7) | 52(96.3) |  | 64(98.5) |  |
 Complex cystic and solid | 6(3.3) | 2(3.7) |  | 1(1.5) |  |
Orientation | Â | Â | 0.01 | Â | 0.22 |
 Parallel | 161(89.0) | 41(75.9) |  | 54(83.1) |  |
 Not parallel | 20(11.0) | 13(24.1) |  | 11(16.9) |  |
Posterior features | Â | Â | 0.54 | Â | 0.57 |
 No posterior features | 177(97.8) | 52(96.3) |  | 65(100) |  |
 Shadowing /Enhancement | 4(2.2) | 2(3.7) |  | 0 |  |
Calcifications on ultrasound | Â | Â | 0.07 | Â | 0.65 |
 Absent | 136(75.1) | 34(63.0) |  | 47(72.3) |  |
 Present | 45(24.9) | 20(37.0) |  | 18(27.7) |  |
Duct changes | Â | Â | 0.09 | Â | 0.81 |
 Absent | 166(91.7) | 53(98.1) |  | 59(90.8) |  |
 Present | 15(8.3) | 1(1.9) |  | 6(9.2) |  |
Vascularity | Â | Â | 0.14 | Â | 0.79 |
 Absent | 94(51.9) | 22(40.7) |  | 35(53.8) |  |
 Present | 87(48.1) | 32(59.3) |  | 30(46.2) |  |
Imaging-pathology correlation | Â | Â | 0.38 | Â | 0.74 |
 Concordant | 96(53.0) | 25(46.3) |  | 36(55.4) |  |
 Discordant | 85(47.0) | 29(53.7) |  | 29(44.6) |  |