Abstract
10618 Background: Successful therapeutic regimens in metastatic breast cancer must balance efficacy and tolerability. D and C is an active and commonly used doublet in this setting. D upregulates thymidine phosphorylase and thus potentiates the anti-tumor effects of C. A schedule with split, low-dose D in combination with low dose C could improve the therapeutic index of this regimen without compromising its clinical activity. Methods: Patients with previously untreated her2-neu negative metastatic breast cancer were included. A Simon 2-stage Phase II clinical trial was designed to assess the response rate (primary end-point), and toxicity of docetaxel 25 mg/m2 on days 1 and 8 in combination with capecitabine 750 mg/m2 bid on days 1–14 of a 21-day cycle. RECIST criteria were used for response assessment, which was performed every 2 cycles. Results: Thirty-one women have been enrolled. Median age was 55. Twenty patients had hormone receptor positive disease. Sites of metastasis were as follows: bone, 24 patients; liver, 14; lungs or pleura 14. A total of 189 cycles have been delivered (median: 4 cycles, range 1–33). Grade 3 and 4 toxicities were as follows: peripheral neuropathy, 2 patients; edema, 1 patient; skin, 1 patient. Two women had fever without neutropenia. Another patient had a gastric perforation but recovered without sequela. Twenty-two patients are available for response evaluation. One patient with a single bone metastasis had a complete response after chemotherapy followed by radiation. Partial responses were seen in 10 patients, for an overall response rate of 50% (95% CI, 30 to 70). Four women had stable disease and 7 had progressed at the time of first assessment. With a median follow-up of 15 months (range 1–26), the median time to treatment failure (all patients) was 7 months (range 1–26+). Median survival has not yet been reached. Out of 8 patients older than 65, seven were evaluable and 4 had a partial response. Conclusions: Split, low-dose Docetaxel and low-dose Capecitabine is an effective combination in the first-line treatment of patients with metastatic breast cancer. Toxicity with this schedule was minimal, making it an attractive regimen for further study. [Table: see text]