Thank you so much for your reply and great suggestions. To clarify, I was told that taking the letrozole prior to biopsies would invalidate much of histological and genetic testing. Onco type testing was never brought up until after surgery. I was then told it wouldn't be accurate or have much meaning since the surgical pathology tissue was exposed to letrozole. All biopsy tissues and surgical tissues are saved for 10 years by the receiving labs. I am trying to find out if all the different types of testing an Oncotype DX does and see if any of them may be valid with the available tissue. My multiple biopsies with 2 different labs are "not enough tissue" for this test so I am told. My plan now: Awaiting ONCOTYPE DX company to contact me, 2nd opinion from another oncologist, I will contact both labs that hold my biopsy tissues, determine how much each have and if combining them may be enough for part or all of the ONCOTYPE DX testing. Again, I appreciate your interest and time put into this.