Neoadjuvant treatment with paclitaxel and epirubicin in invasive breast cancer: a phase II study.

BACKGROUND AND OBJECTIVES: The modern management of locally advanced breast cancer includes a multimodal approach consisting of neoadjuvant chemotherapy (usually given as initial treatment), surgery, radiotherapy and adjuvant hormone therapy. This therapeutic approach converts many patients with initially unresectable disease to reasonable surgical candidates, with acceptable rates of loco-regional disease control. Induction of a pathological complete response (pCR) with modern chemotherapy agents or combined with immunotherapy, when applicable, should be one of the primary goals of neoadjuvant therapy in order to achieve better disease-free and overall survival in this subset of patients. Neoadjuvant chemotherapy is now standard for patients with locally advanced breast cancer, and this method of treatment has been extended to patients with earlier disease without affecting the treatment outcome. The objectives of this study were: (1) to conduct a phase II study to assess the efficacy and availability of epirubicin and paclitaxel in the neoadjuvant setting in women with locally advanced or high tumour-to-breast ratio breast cancer (no patient in either of these subgroups was a candidate for breast-conserving surgery prior to chemotherapy); (2) to evaluate the incidence of clinically relevant toxicity and, in particular, cardiac toxicity after treatment with an epirubicin + paclitaxel regimen in this group of patients.
METHODS: In this open-label, phase II, single-centre trial carried out in a university-affiliated tertiary-care municipal hospital, the rate of objective response, evaluated by clinical and pathological examinations, was the primary endpoint of the study. Other endpoints were the rates of breast-conserving surgery, local recurrence, disease-free survival and overall survival. Sixty patients were enrolled from September 1998 to September 2003 with a median follow-up of 56 months (range 16-96). All 60 women met the criteria for inclusion and agreed to participate in the study. They were diagnosed as having locally advanced or high tumour-to-breast ratio breast cancer that did not initially permit breast-conserving surgery. Epirubicin 75 mg/m(2) and paclitaxel 175 or 200 mg/m(2) were administered for five courses. Rates of adverse events were also analysed.
RESULTS: Eight patients experienced a pCR, five had a pathological partial response with an almost complete pathological response, and 39 were able to undergo breast-conserving surgery. Adverse effects were mostly of grade 1 or 2 severity. The most common adverse reactions were fatigue and neutropenic fever. One patient developed local recurrence during the median 56-month follow-up. Among examined biological markers, only estrogen receptor negativity was a strong predictor of a pCR. The rates of disease-free and overall survival following the neoadjuvant combination were similar for those who had tumours positive for the estrogen receptor and those who were negative for this.
CONCLUSION: Treatment with a combination of epirubicin and paclitaxel enabled lumpectomy in a substantial proportion of women who were previously deemed to not be suitable candidates for breast-conserving surgery. Clinical responses were not influenced by the initial tumour volume, and the only statistically significant predictor of pCR was the estrogen receptor status of the tumour.