Mitoxantrone, 5-fluorouracil, and high dose leucovorin (NFL) versus intravenous cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) in first-line chemotherapy for patients with metastatic breast carcinoma: a randomized phase II trial.

BACKGROUND

Previous Phase II studies using the combination of mitoxantrone, 5-fluorouracil, and high dose leucovorin (NFL) in the treatment of metastatic breast carcinoma have shown this regimen to be active and well tolerated. In this randomized Phase II study, the authors compared the NFL regimen with a standard CMF regimen in the first-line therapy of patients with metastatic breast carcinoma.

METHODS

One hundred twenty-eight women receiving their first chemotherapy for metastatic breast carcinoma were entered into this randomized study. Sixty-four patients were treated with NFL: mitoxantrone 12 mg/m2 IV on Day 1; leucovorin 300 mg IV over 30-60 minutes on Days 1, 2, and 3, immediately preceding administration of 5-fluorouracil; and 5-fluorouracil 350 mg/m2 IV bolus on Days 1, 2, and 3. Sixty-four patients received CMF: cyclophosphamide 600 mg/m2 IV on Day 1; methotrexate 40 mg/m2 IV on Day 1; and 5-fluorouracil 600 mg/m2 IV on Day 1. Both regimens were repeated at 21-day intervals; responding patients received at least 8 courses.

RESULTS

Patients treated with NFL had a higher response rate than patients treated with the CMF regimen (45% vs. 26%, respectively; P = 0.021). Median duration of response was 9 months with NFL and 6 months with CMF (P = 0.10); 11 patients had long responses (>12 months) with NFL versus 4 patients with CMF (P = 0.06). Median survival was similar for both groups. Both regimens were well tolerated, with infrequent Grade 3 or 4 toxicities.

CONCLUSIONS

NFL is an active, well-tolerated regimen for the treatment of metastatic breast carcinoma; it produced a higher response rate than the CMF regimen used in this study. Although more intense CMF regimens or regimens containing doxorubicin would likely increase the response rate, they would almost certainly do so with the consequence of greater toxicity as compared with NFL. NFL is an excellent initial palliative treatment option for elderly patients or patients who have exhibited poor tolerance for other chemotherapy regimens.