A randomized study of epirubicin monotherapy every four or every two weeks in advanced breast cancer. A Hellenic Cooperative Oncology Group study.
PURPOSE
To evaluate the impact on the response rate in patients with advanced breast cancer (ABC) of the doubling of the dose intensity (DI) of epirubicin monotherapy.


PATIENTS AND METHODS
From January 1991 until April 1996, 167 patients with ABC were randomized to receive epirubicin (110 mg/m2) either every four (81 patients, group A) or every two weeks (86 patients, group B). Filgrastim (5 micrograms/kg/daily) was administered prophylactically on days 2-12 of each cycle.


RESULTS
The two groups were equally balanced in terms of major patient and tumor characteristics. Even though the median cumulative dose of epirubicin was identical in the two groups (651 mg/m2), the median DI of epirubicin was doubled in group B (27.2 vs. 52.9 mg/m2/wk, respectively). The complete response (CR) rate was significantly increased in group B (5%, 95% CI: 0.16%-9.84% vs. 17%, 95% CI: 8.9%-25.08%, P = 0.011), although overall response rates were similar (49% vs. 53%, P = 0.5957). Also, there was no significant difference in the incidence of grade 3-4 toxicity between the two groups. After a median follow-up of 25 months (range, 0.43-43.3+) no significant difference was observed in the duration of response (median, 10 months vs. 8.5 months, P = 0.5130), time to progression (median, 7.2 months vs. 7.4 months, P = 0.2970) or survival (median, 14.6 months vs. 14.9 months, P = 0.4483). Logistic regression analysis showed that performance status was a significant variable for response (P = 0.0068) and multivariate analysis using the Cox proportional hazards model revealed that performance status was significant for survival (P = 0.0049), while the presence of multiple metastases (P = 0.0020) was significant for time to progression.


CONCLUSION
Doubling the planned DI of epirubicin monotherapy significantly increases the CR rate but has no influence on time to progression or survival in patients with ABC.