Library

Notes: Abstract 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.

Notes: Abstract Purpose: In a previous phase I study we found the MTDs of paclitaxel and cisplatin when given together weekly, with or without G-CSF support, in patients with advanced solid tumors. The present study was conducted to define the toxicity and efficacy of this regimen, when used with G-CSF support, in chemotherapy-naive or pretreated patients with advanced breast cancer, and to compare the antiproliferative activity of paclitaxel-cisplatin and paclitaxel-doxorubicin combinations on two human breast cancer cell lines. Methods: Patients with metastatic breast cancer received weekly paclitaxel (as a 3-hour IV infusion) at the dose of 85 mg/m2 (75 mg/m2 in pretreated women) followed by cisplatin (40 mg/m2) for a minimum of 6 weeks. An additional 6 weekly cycles were delivered in patients showing absence of documented disease progression after the first 6 weeks. After the 12th cycle only patients who had shown a substantial tumor shrinkage received 6 further cycles. G-CSF 5 μg/kg was also given, SC on days 3 to 5 of each week, for the whole duration of chemotherapy. The combination of paclitaxel with cisplatin or doxorubicin was also tested in vitro on two breast cancer cell lines (MCF-7 and MDAMB-231). Results: Forty-three women with metastatic breast cancer entered this trial between June 1995 and January 1997. Twenty-seven patients were previously untreated for their metastatic disease (but 23 had previously received adjuvant chemotherapy). The dominant site of disease involvement was visceral in 23, bone in 13, and soft tissues in 7 patients. Seven complete and 15 partial responses were observed in unpretreated patients, while no complete and 6 partial responses were achieved in the pretreated population. The overall response rate, assessed on an 'intent to treat' basis, was 81% (26% CRs) in patients unpretreated for metastatic disease and 37% in those who had received one or more previous chemotherapy regimens. Eighteen responder patients had previously received anthracyclines either as adjuvant chemotherapy (12) or in the treatment of metastatic disease (6). At a median potential follow-up of 12 (range, 3–21) months, 14/27 unpretreated and 12/16 pretreated patients had shown disease progression. The median time to treatment failure was 13 and 7 months, respectively, in the 2 subgroups. The 1-year survival probability was 95% in unpretreated patients. The treatment showed a moderate toxicity in both subgroups of patients. Both hematological toxicity and peripheral neuropathy occurred more frequently in pretreated patients. Treatment-related deaths did not occur, and severe myelosuppression was observed only in pretreated patients with massive liver involvement. Delays in chemotherapy administration were very uncommon, especially during the first 6 treatment cycles, and the average actually delivered dose intensity exceeded 90% in unpretreated patients. The in vitro data on MCF-7 and MDA-MB-231 human breast cancer cell lines showed that exposure to the combination of cisplatin and paclitaxel produced a tumor cell killing similar to that achievable with equivalent concentrations of doxorubicin and paclitaxel. Conclusions: Weekly paclitaxel and cisplatin with G-CSF support is an active and particularly well tolerated treatment for patients with either unpretreated or pretreated metastatic breast cancer. This approach seems quite effective also in patients relapsing after anthracycline-based adjuvant chemotherapy. In view of the negligible hematological toxicity associated with this regimen, further clinical trials testing the addition of non cross-resistant drugs to this combination should be performed.