Other Tests to Help Determine the Type of Drug Therapy

Oncotype DX- a 21-Gene Assay for Tumor Proliferation - This is a type of test that allows for special studies to be carried out on a hormone-sensitive (estrogen and/or progesterone receptor positive) breast tumor. It can performed on the tissue obtained from a breast biopsy or the tissue removed at the time of lumpectomy or mastectomy.  This study evaluates the number of genes that are associated with a tumor's ability to proliferate.  Tumors that have a high concentration of these proliferative genes tend to respond better to chemotherapy with antiestrogen therapy while tumors that have a low concentration of these types of genes do just as well with antiestrogen treatment alone.

The Mamma Print - This is a similar genetic analysis of the tumor but involves the use of 70 genes which have been shown to predict breast cancer prognosis and response to treatments.