Table 10 Multivariate Cox regression analyses of overall survival for tumor grades of T1c breast cancer patients in the matched cohort

SURGERY

 Breast-conserving

reference

reference

reference

 Total mastectomy

0.63(0.26–1.52)

0.31

0.51(0.37–0.71)

 < 0.0001

0.63(0.49–0.80)

 < 0.01

 Modified radical mastectomy

1.04(0.39–2.78)

0.94

0.60(0.39–0.93)

0.02

0.57(0.42–0.79)

 < 0.01

RADIATION

 No

reference

reference

reference

 Yes

0.43(0.18–1.01)

0.05

0.40(0.29–0.55)

 < 0.0001

0.43(0.34–0.55)

 < 0.0001

CHEMOTHERAPY

 No

reference

reference

reference

 Yes

0.78(0.48–1.28)

0.33

0.53(0.43–0.66)

 < 0.0001

0.44(0.37–0.53)

 < 0.0001

SUBTYPE

 HoR + /HER2-

reference

reference

reference

 HoR + /HER2 + 

1.70(0.92–3.14)

0.09

1.53(1.17–2.01)

 < 0.01

1.26(0.96–1.65)

0.09

 HoR-/HER2 + 

6.54(0.88–48.72)

0.07

2.16(1.30–3.59)

 < 0.01

1.14(0.79–1.63)

0.49

 HoR-/HER2-

1.58(0.61–4.07)

0.34

2.05(1.53–2.73)

 < 0.0001

1.81(1.50–2.20)

 < 0.0001

AGE (year)

 < 60

reference

reference

reference

 ≥ 60

3.38(1.98–5.77)

 < 0.0001

3.68(2.82–4.81)

 < 0.0001

2.19(1.81–2.66)

 < 0.0001