SAN ANTONIO--First-line chemotherapy with docetaxel(Drug information on docetaxel) (Taxotere) produced response rates as high as 68% in a series of studies involving patients with advanced, metastatic breast cancer.
Two evaluations of a 100 mg/m² dose of docetaxel resulted in identical 68% response rates in a total of 68 patients. The response rate dropped to 52% in an evaluation of a 75 mg/m² dose, Dr. Pierre Kerbrat reported at the San Antonio Breast Cancer Symposium.
The three studies were conducted by the European Organization for Research and Treatment in Cancer (EORTC) Clinical Study Group (CSG). Collectively, the studies enrolled 110 patients, 99 of whom were evaluable for responses.
All patients had measurable metas-tases, and about a third had metastatic involvement of at least two organs, said Dr. Kerbrat, a medical oncologist at the Eugene Marquis Center, Rennes, France. None of the patients had received primary chemotherapy, but more than half had received prior adjuvant chemotherapy.
The first trial, CSG1, included 31 evaluable patients treated with the higher dose of docetaxel every 3 weeks; CSG3 evaluated 37 patients who received the higher dose preceded by 1 day by pre-medication with corticosteroids and histamine antagonists. The second trial, CSG2, evaluated the lower docetaxel dose in 31 patients. No patient in any of the three groups received growth factors.
The 68% overall response rate in the 100 mg/m² groups included five complete responders in CSG1 and two in CSG3. Four patients had complete responses in CSG2. Major responses were seen in 70% to 75% of patients with visceral and liver metastases in the high-dose studies, compared with 52% and 44% in the 75 mg/m² group.
The median duration of response was 44 weeks in CSG1 and 34 weeks in CSG2. Median response duration has not been reached in CSG3 but has ranged between 9 and 36 weeks, Dr. Kerbrat said.