Table 1.

Summary of invasive breast cancer occurrence in tamoxifen and placebo arms in the BCPT by October 1, 2010, for all and patients with ER+ tumors during and after the treatment period

Invasive cancersHR (95% CI)Cox (P)
A. Complete trial population
All patients
Overall follow-up (events: n = 242)
 Placebo (n = 134)10.076
 Tamoxifen (n = 108)0.80 (0.62–1.02)
During treatment period (events: n = 93)
 Placebo (n = 49)10.589
 Tamoxifen (n = 44)0.89 (0.60–1.34)
Posttreatment period (events: n = 149)
 Placebo (n = 85)10.067
 Tamoxifen (n = 64)0.74 (0.53–1.02)
ER-positive
Overall follow-up (events: n = 187)
 Placebo (n = 108)10.028
 Tamoxifen (n = 79)0.72 (0.54–0.97)
During treatment period (events: n = 75)
 Placebo (n = 42)10.290
 Tamoxifen (n = 33)0.78 (0.50–1.23)
Posttreatment period (events: n = 112)
 Placebo (n = 66)10.048
 Tamoxifen (n = 46)0.68 (0.47–0.996)
B. IHC subset
Overall follow-up (n = 179)
 Placebo (n = 100)10.100
 Tamoxifen (n = 79)0.78 (0.58–1.05)
ER-positive (n = 139)
 Placebo (n = 85)10.007
 Tamoxifen (n = 54)0.63 (0.45–0.88)
ER-negative (events: n = 40)
 Placebo (n = 15)10.127
 Tamoxifen (n = 25)1.65 (0.87–3.12)