Opinion on the use of the antitumor drug trastuzumab (Herceptin) in patients with metastatic breast cancer in the county Mecklenburg-Vorpommern.

The recombinant humanized anti-HER-2 monoclonal antibody trastuzumab (Herceptin) is directed against the human epidermal growth factor receptor on the surface of breast cancer cells. Herceptin was approved in Germany in September 2000 after evaluation in clinical trials involving women with metastatic breast cancer who had tumors overexpressing HER-2/neu. A prerequisite for its use is the diagnosis of the HER-2/neu receptor status in individual patients because trastuzumab is only effective in patients with a high (score +3) overexpression of the HER-2/neu receptor. The only approved diagnostic method is the immunohistochemical DAKO-Hercep test. Clinical experience with this novel biological agent has been obtained in 2 Phase III trials involving 469 and 222 patients, where trastuzumab was used as first- or second-line therapy. The addition of trastuzumab to chemotherapy regimens was associated with longer time to progression, a higher rate and duration of response and longer survival. When used as a single agent in metastatic breast cancer that had progressed after chemotherapy, there was an overall response rate of 15%. The median duration of response was 9.1 months and median survival was 13 months. Unwanted effects included potentially severe cardiotoxicity and in 40% of patients infusion-associated fever and/or shivering that usually occurred only during the first infusion. In patients with moderate HER-2/neu expression, unwanted drug effects outweigh a relatively weak therapeutic effect. In cases of high overexpression, the cancer may go into regression and survival may be prolonged with a relatively small impairment in the life quality. The costs of trastuzumab-therapy are high amounting to an additional 48,000 DM per patient per year. Recommendations for diagnosis and therapy in Mecklenburg-Vorpommern have been formulated in discussions between oncologists, practitioners, scientists and regulatory authorities.