[Two cases of recurrent breast cancer with regional lymph node metastases showing a complete response to trastuzumab and paclitaxel treatment].

We report two cases of recurrent breast cancer with regional lymph node metastases that responded completely to treatment with trastuzumab and paclitaxel. Case 1: A 52-year-old woman, who presented with left breast cancer, underwent mastectomy and axillary lymph node dissection in July 2002. Pathological findings were as follows: invasive ductal carcinoma (scirrhous type), 2.2 cm in size, histological grade 3, positive invasion to the lymphatic and blood vessels, negative nodal status (0/11), negative ER/PgR status, and overexpression of HER 2/neu. Left axillary lymph node metastasis was noted after five months, ie, in December 2002. Four cycles of chemotherapy with doxorubicin and cyclophosphamide were administered from January 2003; however, they were not effective. The patient showed a complete response after three months of chemotherapy with trastuzumab and paclitaxel. This treatment was stopped in September 2003. She has maintained a complete response for two and a half years and was not administered any further treatment as of February 2006. Case 2: A 59-year-old woman, who presented with right breast cancer, underwent mastectomy and axillary lymph node dissection in May 2002. Pathological findings were as follows: invasive ductal carcinoma (scirrhous type), 1.8 cm in size, histological grade 2, positive invasion to the lymphatic and blood vessels, negative nodal status (0/5), positive ER and uncertain PgR status, and overexpression of HER 2/neu. She had received adjuvant hormonal therapy with tamoxifen; however, a right supraclavicular lymph node metastasis was noted in October 2004. Treatment with exemestane was not effective. However, a complete response was observed with trastuzumab and paclitaxel for four months. She has maintained a complete response for six months and was not administered any further treatment as of February 2006.