Table 5 Univariate and multivariate analyses of distant metastasis

Age at diagnosis, years (ref =  < 40)

  ≥ 40

0.694 (0.380- 1.300)

0.241

Clinical T stage before NAC (ref = cT1)

 cT2-4

1.071 (0.270- 7.150)

0.931

Clinical N stage before NAC (ref = cT0)

 cN1-3

2.166 (0.600- 13.870)

0.309

Lymphovascular invasion (ref = absent)

 Present

6.594 (3.610- 12.450)

 < 0.001

4.590 (2.230- 9.830)

 < 0.001

HR + (ref = negative)

 Positive

0.878 (0.500- 1.530)

0.644

HER2⁺(ref = negative)

 Positive

0.516 (0.270- 0.960)

0.038

0.530 (0.250- 1.110)

0.099

Ki-67 before NAC (ref =  < 14%)

  ≥ 14%

1.357 (0.580- 3.740)

0.515

Ki-67 after NAC (ref =  < 14%)

  ≥ 14%

2.606 (1.390- 5.050)

0.004

3.230 (1.520- 7.160)

0.003

Radiologic response of MRI (ref = CR)

 Non-CR

11.429 (3.440- 70.820)

0.001

N/A

0.988

Extent of surgery (ref = total mastectomy)

 Partial mastectomy

0.546 (0.300- 0.960)

0.039

1.400 (0.610- 3.210)

0.426

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

  ≥ 10

0.891 (0.210- 6.050)

0.887

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

  ≥ 10

1.056 (0.260- 7.050)

0.946

Residual microcalcification (ref = absent)

 Present

0.944 (0.366–2.145)

0.897

0.810 (0.200–2.920)

0.755