Table 4 Cox multivariable models for disease-free survival (DFS) and overall survival (OS)

Age at diagnosis (years)

1.00 (0.98–1.02)

0.691

1.01 (0.99–1.04)

0.232

Method of detection

Screen-detected

1.00

1.00

Symptomatic

1.49 (0.91–2.47)

0.115

1.30 (0.76–2.20)

0.334

Stage at diagnosis

I-II

1.00

1.00

III-IV

2.41 (1.43–4.05)

0.001

1.78 (1.00-3.18)

0.05

Neoadjuvant chemotherapy

No neoadjuvant chemotherapy

1.00

1.00

Yes, with a complete response

1.88 (0.44–7.92)

0.391

0.20 (0.04–1.05)

0.06

Yes, with a partial or absent response

2.24 (1.23–4.09)

0.009

1.36 (0.64–2.86)

0.413

Adjuvant chemotherapy

No

1.00

1.00

Yes

1.47 (0.82–2.64)

0.200

0.86 (0.46–1.60)

0.630

Type of surgery

Conservative

1.00

1.00

Radical

0.80 (0.48–1.34)

0.405

0.99 (0.56–1.73)

0.967

Vascular invasion

No

1.00

1.00

Yes

2.95 (1.67–5.20)

< 0.001

2.51 (1.36–4.62)

0.003

Histologic type

Non-special type (NST)

1.00

1.00

Metaplastic

3.44 (1.46–8.10)

0.005

2.73 (1.00-7.40)

0.049

Lobular

1.66 (0.60–4.58)

0.330

1.84 (0.60–5.63)

0.287

Others

2.53 (1.41–4.53)

0.002

2.62 (1.40–4.87)

0.002

Histologic grade

1–2

1.00

1.00

3

0.69 (0.35–1.39)

0.303

0.84 (0.41–1.75)

0.647

Ki-67

< 20%

1.00

1.00

≥ 20%

1.54 (0.63–3.81)

0.344

1.29 (0.47–3.55)

0.619

TILS*

< 30%

1.00

1.00

≥ 30%

1.00 (0.62–1.94)

0.739

0.30 (0.12–0.76)

0.011