BRCA 1 and ovarian cancer

I am a 50 year old surviving 1 year from stage 4 ovarian cancer. Recently, I tested positive for BRCA 1 gene. My oncologist and internist are pushing the use of tamoxifen even tho BRCA 1 doesn't seem to be blocked by that drug. Just wondered if anyone else had this "combo" and what treatments they received. I would like to seek a second opinion, haven't found a doctor yet. As of today, the MRI showed an emlarged lymph node on the right side...I'm being sent back to the breast oncologist now. Still waiting for an appt.
I'm open to suggestions.