[Combination treatment with trastuzumab and Paclitaxel as primary therapy for advanced breast cancer]

Despite many recent reports on the effects of trastuzumab for breast cancer, many problems remain regarding combination drug treatment and its significance. We report our experience with advanced breast cancer patients who received combination therapy with trastuzumab+paclitaxel.

Three patients with human epidermal growth factor receptor 2(HER2)-positive advanced breast cancer were the subjects. Combination therapy with trastuzumab and paclitaxel was carried out as a primary therapy, and its therapeutic effects were evaluated based on image findings, tumor markers and observation of resected specimens.

The primary tumors in the three patients were all clinically complete response (cCR). Those in two surgically treated patients were near pathologically complete response (pCR), ie, a small amount of cancer cells remained in the galactophore, whereas the histological therapeutic effect was Grade 2b. In two patients with liver metastases, the metastatic tumor disappeared on the image after the therapy. In two patients whose tumor marker was increased at the first examination, the level of increase was markedly lowered by the therapy. Neither infusion reaction nor heart functional impairment was found in any of the three patients.

For patients with advanced breast cancer, a regimen containing trastuzumab would produce significant therapeutic effects if the cancer is HER2-positive. The regimen would also contribute to the prognosis of such patients since it might produce pCR. Since the risk of severe adverse effects is low and the treatment with trastuzumab can be conducted safely as an ambulatory treatment, high patient QOL seems possible. These findings suggest that combination therapy with trastuzumab+paclitaxel is effective as a primary therapy for HER2-positive advanced breast cancer.