 II. To investigate treatment resistance e.g., expression of amphiregulin, epidermal growth factor receptor EGFR, using molecular and immunohistochemical analyses of blood and tumor samples of pre- and post- when available treatment tissues. Microarray analyses to quantitate the expression of specific estrogen-responsive genes e.g. thyroid transcription factor 1 TTF1 and PDZK1 will also be performed. 