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 (Herce ptin) is directed against the human epidermal growth factor receptor on the surface of breast cancer cells. Herceptin was approved in Germany in Septe mber 2000 after evaluation in clinical trials involving women with metastat ic breast cancer who had tumors overexpressing HER-2/neu. A prerequisite fo r its use is the diagnosis of the HER-2/neu receptor status in individual p atients because trastuzumab is only effective in patients with a high (scor e +3) overexpression of the HER-2/neu receptor. The only approved diagnosti c method is the immunohistochemical DAKO-Hercep test. Clinical experience w ith this novel biological agent has been obtained in 2 Phase III trials inv olving 469 and 222 patients, where trastuzumab was used as first- or second -line therapy. The addition of trastuzumab to chemotherapy regimens was ass ociated with longer time to progression, a higher rate and duration of resp onse and longer survival. When used as a single agent in metastatic breast cancer that had progressed after chemotherapy, there was an overall respons e rate of 15%. The median duration of response was 9.1 months and median su rvival was 13 months. Unwanted effects included potentially severe cardioto xicity and in 40% of patients infusion-associated fever and/or shivering th at usually occurred only during the first infusion. In patients with modera te HER-2/neu expression, unwanted drug effects outweigh a relatively weak t herapeutic 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 t o an additional 48,000 DM per patient per year. Recommendations for diagnos is and therapy in Mecklenburg-Vorpommern have been formulated in discussion s between oncologists, practitioners, scientists and regulatory authorities .