Dose-response relationship of epirubicin-based first-line chemotherapy for advanced breast cancer: a prospective randomized trial.

PURPOSE

We compared prospectively the antitumor efficacy of two combination chemotherapy regimens with two different dose levels of epirubicin as first-line treatment for advanced breast cancer.

PATIENTS AND METHODS

One hundred forty-one fully assessable patients were randomized to receive either our intensified schedule (group A, n = 71) of epirubicin 50 mg/m2 on days 1 and 8 (every 3 weeks), or a non-intensified program (group B, n = 70) in which epirubicin was only administered on day 1. Both groups also received fluorouracil (5 FU) and cyclophosphamide 500 mg/m2 on day 1 of each course.

RESULTS

A statistically significant difference in response rate was observed (69% in group A v 41% in group B, P < .001) for both locally advanced (LA) and recurrent metastatic (RM) disease. Response duration (22 v 14 months, P < .01) and time to progression (TTP; 19 v 8 months, P < .02) were also significantly improved. Overall survival was similar in both groups. However, univariate and/or multivariate analyses showed a meaningful relationship between type of treatment allocated, dose-intensity (DI) of epirubicin, and response rate, as well as between TTP and survival. Ultimately, TTP and survival were also influenced by further treatment modalities, namely, hormonotherapy and chemotherapy.

CONCLUSION

This study validates prospectively the concept of a dose-response relationship for an anthracycline-based chemotherapy in previously untreated advanced breast cancer.