Table 3 Cox regression analysis of ER:PR-B interactions and PR-B expression influencing relapse-free survival stratified by adjuvant endocrine agent class taken

From: Improved relapse-free survival on aromatase inhibitors in breast cancer is associated with interaction between oestrogen receptor-α and progesterone receptor-b

Endocrine agent

ER:PR-B interaction

Relapse (%)

HR

95% CI

p Value

Tamoxifen

Low

9 (24.3)

1.043

0.348–3.135

0.939

High

5 (19.2)

   

Aromatase inhibitor

Low

20 (30.8)

4.831

1.942–12.048

0.001

High

6 (7.1)

   

Test for interaction

    

0.031

 

PR-Bexpression

Relapse (%)

HR

95% CI

p Value

Tamoxifen

Low

13 (36.1)

8.929

1.164 – 66.667

0.035

High

1 (3.7)

   

Aromatase inhibitor

Low

22 (23.9)

2.874

0.984 – 8.403

0.053

High

4 (7.0)

   

Test for interaction

    

0.355

  1. Percentages refer to the number of patients with high or low ER:PR-B interactions or PR-B expression that had relapsed on endocrine treatment. Bold indicates significant p values