Dear TATDEL: When chemotherapy is given in the postoperative setting for invasive early breast cancer it typically lasts approximately 3 to 6 months. Four cycles of every 3-week AC chemotherapy followed by 12 weekly Taxol treatments does take approximately 6 months. Herceptin, which is a monoclonal antibody treatment, is now frequently incuded in the postoperative treatment when the cancer is found to have overexpression of Her2/neu. Although the optimal duration of Herceptin treatment in this situation is not known, the relevant clincal trials that have been reported to date have administered the Herceptin for about 1 year. Hormonal therapy, which is generally recommended in hormone receptor positive breast cancer, usually lasts at least 5 years.