Docetaxel and mitoxantrone, versus docetaxel mitoxantrone and letrozole as first-line therapy in advanced breast cancer: A randomized study

Abstract

722 Background: Doxetaxel (DCT) and mitoxantrone (MX) are highly active and potentially synergistic agents in the treatment of metastatic breast cancer (MBC). Letrozole, a nonsteroidal, third-generation aromatase inhibitor has shown efficacy in the treatment of postmenopausal women with advanced disease, producing objective tumor response rates of approximately 25% after failure of previous therapy. This study evaluates the combination of DCT and MX with or without letrozole in patients with MBC to determine the efficacy and toxicity of this therapy. Methods: One hundred and eleven (median age 62 yrs), postmenopausal previously untreated patients with MBC were studied. The patients were randomly assigned to receive the combination of Docetaxel 80 mg/m2, Mitoxantrone 12 mg/m2 every three weeks and Letrozole 2.5 mg daily (group A, n=56 pts), or Docetaxel 80 mg/m2 and Mitoxantrone 12 mg/m2, every three weeks (group B, n=55 pts). Response was assessed according to UICC criteria at 12 and 24 weeks. Results: The treatment with DCT and MX was well tolerated. Toxicity was low in both arms, without statistical difference: 24 grade I and 18 grade 2 cases were observed in Group A vs 22 grade I and 17 grade 2 cases in group B. At 24 weeks, complete remissions were seen in 9.8% of group B and 5.8% of group A, partial remissions were observed in 58.8% and 53 %, respectively; and stable disease was achieved in 9.8% and 13.7%, respectively. Disease progressed in 21.5% of group B patients and 27.4% of group A patients. None of these differences were significant Conclusions: Intensifying standard docetaxel and mitoxantrone first-line therapy in advanced breast cancer patients with letrozole hormone therapy may be of little benefit in terms of response rate. However, in the chemotherapy-hormonotherapy combination arm, there is a trend for more objective responses. No significant financial relationships to disclose.