Adding capecitabine (xeloda) to docetaxel (taxotere) in patients with early breast cancer leads to more toxicities and does not improve the efficacy of treatment, a German scientist told the 6th European Breast Cancer Conference in Berlin today. Previously, such a combination had improved patient survival in metastatic disease, where the cancer has spread to other parts of the body.
Capecitabine is a drug that inhibits DNA synthesis and slows the growth of tumour tissue, and docetaxel is a taxane which stops microtubules in cancer cells breaking down, thus clogging the cells preventing further cancer cell production.
Professor Gunter von Minckwitz, Chairman of the German Breast Group, set out to look at the use of the combination in early breast cancer, recruiting 1510 patients with previously untreated primary tumours. Each received the normal preoperative treatment of four cycles of epirubicin and cyclophosphamide. They were then randomly given either four cycles of docetaxel alone, four cycles of simultaneous docetaxel and capecitabine, or four cycles of docetaxel followed by four cycles of capecitabine. "If capecitabine were to improve outcomes, we wanted to see how best to use it; simultaneously or in sequence", said Professor von Minckwitz.
The plan to study the way in which the tumour had reacted to the chemotherapy before surgery had to be abandoned when they found "no difference in efficacy between the three arms of the trial with regard to pathologic response, clinical response, and rate of breast conservations". The overall rate of success, a lack of cancer in the breast or lymph nodes, was 29.7%.
The length of treatment appeared to make no difference either. What the scientists did find, unfortunately, was that the addition of capecitabine to the chemotherapy regime produced more non-haematological toxicities. These included; hand-foot syndrome (a skin reaction that appears on the palms of the hands and soles of the feet), increased rates of nail growth, inflammation of the mucous lining the mouth and throat, and diarrhoea.
The scientists say that they would not recommend adding capecitabine to docetaxel as preoperative treatment in early breast cancer, not only because of the lack of extra efficacy and the additional toxicities that it produces, but also because the prolongation of chemotherapy has the effect of reducing patient compliance.
"Given all these factors we would recommend staying with current standard treatments; epirubicin and cyclophosphamide followed by a taxane, or TAC, another commonly used three-drug combination of docetaxel, doxorubicin and cyclophosphamide," concluded Professor von Minckwitz.