Table 2.

Subgroup analysis of OS and BCSS outcomes.

Variables	OS		BCSS
	HR (95% CI)	p-valuea	HR (95% CI)	p-value
Age
<35	0.38 (0.24–0.61)	<0.001	0.38 (0.23–0.62)	<0.001
35–49	0.61 (0.51–0.73)	<0.001	0.62 (0.52–0.75)	<0.001
50–69	0.54 (0.48–0.61)	<0.001	0.55 (0.49–0.62)	<0.001
≥ 70	0.62 (0.53–0.72)	<0.001	0.66 (0.57–0.76)	<0.001
T Stage
T1	0.46 (0.36–0.60)	<0.001	0.45 (0.35–0.59)	<0.001
T2	0.53 (0.47–0.61)	<0.001	0.55 (0.48–0.63)	<0.001
T3	0.57 (0.48–0.68)	<0.001	0.57 (0.47–0.69)	<0.001
T4	0.66 (0.59–0.75)	<0.001	0.64 (0.56–0.73)	<0.001
N Stage
N0	0.52 (0.44–0.61)	<0.001	0.53 (0.44–0.63)	<0.001
N1	0.55 (0.49–0.62)	<0.001	0.55 (0.48–0.62)	<0.001
N2	0.54 (0.44–0.65)	<0.001	0.53 (0.43–0.65)	<0.001
N3	0.72 (0.60–0.85)	<0.001	0.70 (0.58–0.83)	<0.001
Grade
High, I	0.55 (0.39–0.77)	<0.001	0.45 (0.31–0.65)	<0.001
Intermediate, II	0.56 (0.49–0.64)	<0.001	0.56 (0.48–0.64)	<0.001
Low, III	0.60 (0.54–0.66)	<0.001	0.60 (0.54–0.67)	<0.001
Undifferentiated, IV	0.55 (0.16–1.86)	0.334	0.86 (0.23–3.19)	0.820
Distant Metastasis
Bone only	0.51 (0.45–0.58)	<0.001	0.52 (0.45–0.59)	<0.001
Liver only	0.75 (0.57–0.99)	0.041	0.74 (0.56–0.99)	0.042
Lung only	0.58 (0.46–0.73)	<0.001	0.53 (0.41–0.67)	<0.001
Brain only	0.31 (0.14–0.69)	0.004	0.29 (0.13–0.65)	0.003
Other site	0.59 (0.46–0.75)	<0.001	0.55 (0.42–0.71)	<0.001
Multiple sites	0.61 (0.53–0.70)	<0.001	0.62 (0.54–0.71)	<0.001
ER Status
Negative	0.54 (0.47–0.62)	<0.001	0.56 (0.49–0.64)	<0.001
Positive	0.60 (0.55–0.66)	<0.001	0.58 (0.53–0.64)	<0.001
PR Status
Negative	0.63 (0.56–0.70)	<0.001	0.64 (0.57–0.71)	<0.001
Positive	0.55 (0.49–0.61)	<0.001	0.53 (0.47–0.59)	<0.001
HER2 Status
Negative	0.59 (0.54–0.64)	<0.001	0.58 (0.53–0.64)	<0.001
Positive	0.52 (0.44–0.61)	<0.001	0.54 (0.45–0.64)	<0.001
Radiation
No	0.68 (0.62–0.75)	<0.001	0.68 (0.62–0.75)	<0.001
Yes	0.43 (0.38–0.49)	<0.001	0.43 (0.38–0.49)	<0.001
Chemotherapy
No	0.61 (0.54–0.69)	<0.001	0.60 (0.53–0.68)	<0.001
Yes	0.56 (0.50–0.62)	<0.001	0.56 (0.51–0.63)	<0.001

^aMultivariant Cox regression model.

All HRs refer to Surgery versus non-surgery in the subgroup analysis.

CI, confidence interval; BCSS, breast cancer specific survival.