Affecting an estimated 331,530 women in the United States each year, breast cancer remains one of the most well-known and common cancers experienced. Breast cancer is staged from I to IV with I through III describing varying degrees of localized cancer, and IV representing the metastatic stage. Treatment varies greatly depending on stage, location, and tumor characteristics. Testing for hormone receptors and HER2 genes helps
to guide treatment by helping to predict which therapies the tumor will respond best to.