This study of 1036 primary tumours confirms the association between activated AKT, MAPK and ERα phosphorylation status in postmenopausal breast cancer patient, but does not corroborate their prognostic power for DFS or OS in the entire PathIES study, nor their predictive values for these outcomes for patients managed by switched therapy over tamoxifen alone. This evidence concerns the gene ESR1 and neoplasm.