Primary chemotherapy in operable breast cancer with favorable prognostic factors: a pilotstudy evaluating the efficacy of a regimen with a low subjective toxic burden containingvinorelbine, 5-fluorouracil and folinic acid (FLN)

Background: Biological considerations support the use of primary chemotherapy in operable breast cancer; and despite wide variations of used regimens, clinical studies consistently show a significant tumor response allowing breast conservation in many patients otherwise canditates for mastectomy. We investigated the efficacy and the acceptance of a combination chemotherapy with vinorelbine, 5-fluorouracil and high-dose folinic acid in operable breast cancer with favorable prognostic factors and tested the relationship of hormone receptor status, Ki67, p53, c-erbB2 and bcl-2 with treatment response. Patients and methods: Thirty-nine patients (median age 51 years, range 36-71 years), eight with T-1, twenty-eight with T-2 and two with T-3 lesions, were treated with 5-fluorouracil (350 mg/m(2), i.v. on day 1 to 3) preceded by folinic acid (100 mg/m(2) i.v. on day 1 to 3) and vinorelbine, given on days 1 and 3 at the dose of 20 mg/m(2) (FLN regimen). Therapy was administered on an outpatient basis every three weeks. Non responders had surgery after three courses, while complete or partial responders underwent surgery after six courses. All but one were evaluable for response and toxicity. Results: Objective responses were observed in 23 of the 38 evaluable patients (61%; 95% CI: 46%-76%): three complete responses (8%) and 20 partial responses (53%). Fifteen patients (39%) had stable disease, of whom nine (23%) had minor response. None of the patients had disease progression during treatment. Objective responses were significantly associated with no expression of estrogen and/or progesteron receptors and > 50% decrease in Ki67 after induction chemotherapy. Tolerance was excellent and none of the patients experienced grade 2 alopecia. Conclusions: The `moderate' efficacy of this regimen might be partially due to the selection of patients with high expression of steroid hormone receptors and low proliferation rate, which have an unfavorable impact on response to this chemotherapy.