Front-line treatment of metastatic breast cancer with docetaxel and epirubicin: a multicenter dose-escalation study. The Greek Breast Cancer Cooperative Group (GBCCG).

PURPOSE

To determine the maximum tolerable dose (MTD) and the dose-limiting toxicity (DLT) of docetaxel (D) in combination with epirubicin (Epi) in patients with advanced breast cancer.

PATIENTS AND METHODS

Forty-seven chemotherapy-naïve metastatic breast cancer patients aged < 75 years with PS (WHO) 0-2 and adequate bone marrow, renal, liver and cardiac function, were enrolled in the study. Epi was given as a five-min bolus i.v. infusion on day 1 (d1) in escalated doses with increments of 10 mg/m2; D was given in a one-hour infusion after appropriate premedication on either day 1 or on day 2 in escalated doses with increments of 10 mg/m2. The patients' median age was 60 years, 42 (89%) had a PS (WHO) 0-1, 16 (34%) were premenopausal and 25 (53%) had visceral disease.

RESULTS

When the two drugs were given on the same day, the MTD1 was reached at the doses of Epi 60 mg/m2 and D 80 mg/m2; administration of G-CSF could not result in a dose intensification. When the drugs were given on two consecutive days, the MTD2 was reached at the doses of Epi 80 mg/m2 (d1) and D 90 mg/m2 (d2). The dose-limiting events were febrile neutropenia and grade 4 neutropenia, which developed in 30 (64%) patients during the study; among 227 delivered cycles grade 3-4 neutropenia occurred in 64 (28%) cycles but only 22 (10%) of them were complicated by fever. There were no septic deaths. Grade 1-2 neurosensory toxicity occurred in nine (19%) patients, mild edema in eight (17%) and allergic reactions in five (11%). Four (9%) patients presented a greater than 10% decrease of LVEF and treatment discontinuation was required in two of them; none of the patients developed congestive heart failure. Nevertheless, one patient suddenly died 10 days after treatment initiation of myocardial ischemia, and this death is considered treatment-related. Five (14.7%) complete and thirteen (38.2%) partial responses (ORR: 53.9%; 95% confidence interval: 36.1%-69.7%) were observed in 34 evaluable patients. Ten (29.4%) and six (17.6%) patients had stable and progressive disease, respectively. The median duration of response and time to tumor progression were five and seven months, respectively. The median survival has not yet been reached.

CONCLUSIONS

The combination of epirubicin and docetaxel is a feasible and well tolerated regimen, but the MTD depends on the administration schedule of the drugs.