Cisplatin-epirubicin-paclitaxel Weekly Administration with G-CSF Support in Advanced Breast Cancer. A Southern Italy Cooperative Oncology Group (SICOG) Phase II Study

Purpose: It has been shown in vitro that both cisplatin and epirubicin increase the antitumor activity of paclitaxel. Weekly administration could give a substantial improvement in the therapeutic index of cisplatin and paclitaxel. This study was aimed at defining the antitumor activity of a weekly cisplatin-epirubicin-paclitaxel (PET) administration in locally advanced or metastatic breast cancer patients.

Patients And Methods: Sixty-eight breast cancer patients with advanced disease, who had not received prior chemotherapy (except adjuvant), received weekly cisplatin 30 mg/sqm, paclitaxel 120 mg/sqm and epirubicin 50 mg/sqm plus G-CSF (day 3-5), for a maximum of 12 cycles. Thirty-five patients had stage IIIB and 33 stage IV disease (14 with visceral metastases).

Results: All patients were evaluable for response on an intent to treat basis. Overall, 21 complete and 38 partial responses have been recorded for an 87% ORR (95% CI = 76-94%). Fourteen CRs and 19 PRs have been registered in the 35 patients with locally advanced disease for a 94% ORR (95% CI = 81-99%) while 7 CRs and 19 PRs were observed in the 33 patients with metastatic disease for a 79% ORR (95% CI-61-91%). Surgery was performed in 33/35 women with locally advanced disease. Four of these patients (11%) showed no invasive cancer on pathologic examination, and in an additional 8 patients tumor < 1 cm was found in the breast. Only 4/33 patients who underwent surgery relapsed. The projected one-year RFS was greater than 80%. At an 11-month median follow-up (range, 3-19), 11 patients had progressed and 5 had died among the 33 patients with metastatic disease, the median progression-free survival in this group being 14 months. Severe hematologic toxicity was uncommon, grade 3-4 neutropenia and thrombocytopenia occurring in 32% and 4% of patients, respectively. Only 2 episodes of neutropenic sepsis were registered. Packed red blood cell transfusions were required in 7 patients. Vomiting, diarrhoea, mucositis and skin toxicity were severe in 6%, 9%, 10%, and 9% of patients, respectively. Peripheral neuropathy was observed in 47% of patients.

Conclusions: The weekly PET administration is a well tolerated and very effective approach in advanced breast cancer patients. It can produce a 40% clinical complete response rate, with a more than 10% pCR rate in patients with T4 disease, and an about 80% ORR in those with distant metastases. A phase III trial comparing PET with a standard every 3 weeks epirubicin-taxol administration is underway.