The present invention relates to a method for predicting the response of a patient diagnosed with
breast cancer to treatment with an
endocrine therapy drug, comprising the steps of: (a) measuring the binding of the
estrogen receptor, obtained from a
breast cancer tumor from said patient, generating a binding profile, said binding profile comprising the binding of the
estrogen receptor from said patient on one or more co-
regulator proteins or functional parts thereof in the presence and absence of one or more added phosphatases, (b) measuring the binding of the
estrogen receptor, obtained from a
breast cancer tumor from said patient, generating a binding profile, said binding profile comprising the binding of the
estrogen receptor from said patient on one or more co-
regulator proteins or functional parts thereof in the presence and absence of added estradiol, and, (c) predicting from said binding profiles the response of said patient to endocrine
drug therapy. The present invention also relates to variant methods hereof and methods for predicting the response of a patient diagnosed with breast
cancer to
drug treatment and methods for individualized
endocrine therapy of a patient diagnosed with an endocrine related
disease. The invention also relates to arrays and kits for carrying out these methods.