Table 2 Details of different subgroups regarding overall survival.

From: Prognostic value of adjuvant chemotherapy for hormone receptor-negative T1a and T1bN0M0 breast cancer patients

Number of risk factor(s)

0

1

2

3

CT

No CT

CT

No CT

CT

No CT

CT

No CT

Before PSM

Number of patients

113

128

332

321

755

494

801

945

Number of 5-year overall deaths

3

4

5

9

30

29

46

126

5-year overall survival rate

97.10%

96.80%

98.30%

97.10%

95.80%

93.90%

94.10%

86.30%

After PSM

Number of patients

113

112

178

200

299

288

627

617

Number of 5-year overall deaths

3

4

2

3

9

17

37

88

5-year overall survival rate

97.10%

96.30%

98.70%

98.40%

96.90%

93.80%

94.00%

85.30%