2000 Update of Recommendations for the Use of Tumor Markers in Breast and Colorectal Cancer: Clinical Practice Guidelines of the American Society of Clinical Oncology (ASCO). The breast cancer tumor marker discussion begins at mid-article (i.e. after the colorectal cancer discussion). When reading the article please note that another medical reference for HER-2 positive is C-erbB-2 positive.

Although ASCO does not "formally" recommend use of many tumor markers an excellent description of each marker as well as its significance is set forth in the article.