If you are going to have surgery to remove the breast cancer before receiving breast cancer treatments, a small piece of the tumor will be removed and sent for testing. If you are going to have a planned needle biopsy, an extra core sample and/or fine needle sample will be taken. If you are going to have a research biopsy, an ultrasound or mammogram will be used to find the tumor and a needle will be inserted into the tumor to collect a piece of tissue.