The present invention is related to a method for analyzing a clinical response of a patient suffering from or at risk of developing a neoplastic disease towards at least one given mode of treatment, said method comprising the steps of: a) obtaining a biological sample from said patient; b) determining, on a non protein basis, the expression level of three genes of interest, said genes being correlated with the Estrogen receptor (ESR) status in the sample, c) comparing the pattern of expression levels determined in (b) with one or several reference pattern(s) of expression levels; and d) predicting therapeutic success for said given mode of treatment in said patient from the outcome of the comparison in step (c); and treating based on said outcome.