Phosphorylated p-70S6K predicts tamoxifen resistance in postmenopausal breast cancer patients randomized between adjuvant tamoxifen versus no systemic treatment

Table 2 Adjusted hazard ratios and tests for interaction between PI3K and/or MAPK pathway markers and tamoxifen

	Variable level	Adjusted hazard ratio^afor tamoxifen versus control (95% confidence interval)	Adjusted P value for interaction
p-AKT (Ser473)	Below median (0 to 1)	0.34 (0.17 to 0.69)	0.16
p-AKT (Ser473)	Above median (2 to 3)	0.68 (0.33 to 1.38)	0.16
p-AKT (Thr308)	Below median (0)	0.42 (0.24 to 0.74)	0.09
p-AKT (Thr308)	Above median (1 to 3)	1.03 (0.43 to 2.50)	0.09
p-mTOR	Below median (0 to 20%)	0.41 (0.23 to 0.71)	0.25
p-mTOR	Above median (21 to 100%)	0.74 (0.31 to 1.76)	0.25
p-ERK1/2	Below median (0)	0.34 (0.18 to 0.63)	0.06
p-ERK1/2	Above median (1 to 100%)	0.87 (0.40 to 1.87)	0.06
p-p70S6K	Below median (0)	0.24 (0.13 to 0.47)	0.004
	Above median (1 to 3)	1.02 (0.48 to 2.21)

ERK, extracellular signal-regulated kinase; MAPK, mitogen-activated protein kinase; mTOR, mammalian target of rapamycine; PI3K, phosphatidylinositol-3-kinase; p, phosphorylated. ^aRecurrence-free interval survival. Models were adjusted for age, T stage, grade, progesterone receptor status and human epidermal growth factor receptor 2 status. Models were stratified for nodal status.

ISSN: 1465-542X