The continuous infusion of fluorouracil presents a superior pharmacological profile than its bolus administration, while vinorelbine is a new drug associated with good clinical activity in pretreated metastatic breast cancer. We investigated the combination of this two antitumor drugs with the aim to determine a tolerant and active second-line therapy in metastatic pretreated patients.
Patients and methods: Fifty six patients pretreated with chemotherapy received a median of six cycles [2-11] of fluorouracil, 700 mg/m2 for 5 day-continuous i.v. infusion and vinorelbine, 20 mg/m2 on days 1 and 6, every three weeks. The inclusion and evaluation criteria required measurable disease by conventional clinical and/or instrumental means.
Findings: Iatrogenic toxicity in 340 administered cycles was mild: stomatitis = 11% (Grade 3 = 5%), constipation and abdominal pain = 12%, G2 neutropenia = 4%, G1 thrombocytopenia = 0.5%. In nine cases moderate infections occurred and six women experienced catheter related complications. Complete and partial remissions were observed in 12% and 36% of evaluable patients, respectively. In particular major tumor regression was documented in 28% of anthracyclines or taxol unresponsive cases.
Conclusions: This drug combination is active in metastatic pretreated breast cancer patients and devoid of serious iatrogenic toxicity. Although it deserves future optimization, for instance with the inclusion of oral fluoropirimidines, it represents a good choice for second-line or non cross-resistant regimens.