Table 4 Univariate and multivariate analyses of regional recurrence

Age at diagnosis, years (ref =  < 40)

  ≥ 40

0.642 (0.320 -1.320)

0.211

Clinical T stage before NAC (ref = cT1)

 cT2-4

1.556 (0.290- 28.910)

0.677

Clinical N stage before NAC (ref = cT0)

 cN1-3

1.390 (0.380 -8.950)

0.667

Lymphovascular invasion (ref = absent)

 Present

7.758 (3.810- 16.910)

 < 0.001

6.000 (2.510- 15.650)

 < 0.001

HR + (ref = negative)

 Positive

0.606 (0.310- 1.160)

0.131

HER2⁺(ref = negative)

 Positive

0.373 (0.170- 0.770)

0.009

0.280 (0.110- 0.690)

0.007

Ki-67 before NAC (ref =  < 14%)

  ≥ 14%

1.958 (0.660- 8.390)

0.282

Ki-67 after NAC (ref =  < 14%)

  ≥ 14%

4.808 (2.180 -11.790)

 < 0.001

7.940 (3.050- 23.400)

 < 0.001

Radiologic response of MRI (ref = CR)

 Non-CR

14.812 (3.140- 264.940)

0.008

N/A

0.988

Extent of surgery (ref = total mastectomy)

 Partial mastectomy

0.490 (0.240- 0.950)

0.039

1.400 (0.510- 3.800)

0.504

Pre-NAC extent of microcalcifications, mm (ref =  < 10)

  ≥ 10

0.545 (0.130- 3.740)

0.458

Post-NAC extent of microcalcifications, mm (ref =  < 10)

  ≥ 10

0.619 (0.150- 4.180)

0.550

Residual microcalcification (ref = absent)

 Present

0.742 (0.213–1.992)

0.592

0.600 (0.100- 2.880)

0.543