Patient-Derived Tumor Xenograft Models of Breast Cancer.

The need for model systems that more accurately predict patient outcome has led to a renewed interest and a rapid development of orthotopic transplantation models designed to grow, expand, and study patient-derived human breast tumor tissue in mice. After implanting a human breast tumor piece into a mouse mammary fat pad and allowing the tumor to grow in vivo, the tumor tissue can be either harvested and immediately implanted into mice or can be stored as tissue pieces in liquid nitrogen for surgical implantation at a later time. Here, we describe the process of surgically implanting patient-derived breast tumor tissue into the mammary gland of nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice and harvesting tumor tissue for long-term storage in liquid nitrogen.