Capecitabine (X) monotherapy as first-line chemotherapy (CT) for metastatic breast cancer (MBC): High efficacy regardless of prior therapy

Abstract

1092 Background: X is one of the most active agents in pretreated MBC. Data on X monotherapy as first-line CT are limited, although a recent randomized phase III trial showed a survival benefit vs oral CMF (Stockler et al SABCS 2006). We retrospectively analyzed MBC pts receiving first-line X at our institution. Methods: Between 01/2002 and 09/2006, 167 pts received X (bid, days 1–14 q3w). Response classifications (improvement in disease [ID], stable disease [SD], or progressive disease [PD]) were as described by Hennessy et al (Ann Oncol 2005). Results: Median age was 68 years (range 34–91). Prior adjuvant therapy included CT in 47% and tamoxifen in 49% of pts. Median interval between initial surgery and MBC was 4.4 years (range 0–39). Before X, most pts (79%) had received endocrine therapy (ET) for MBC (median 2 lines, median duration 2.1 years). Median no. of metastatic sites was 2; bone and visceral metastases were each present in 60% of pts. The initial X dose was 1,500–2,500mg/d in 23%, 3,000mg/d in 47%, and 3,150–4,800mg/d in 29% of pts. ID was seen in 57% of pts (median duration 11.7 months [95% CI 3.8–28.6]). A further 20% had SD for =6 weeks. Median time to X failure (TTF) and OS were 9.0 [95% CI 7.1–11.0] and 25.8 months [95% CI 22.1–29.5], respectively. None of the following influenced TTF: age (<70/=70y), prior adjuvant CT (yes/no), prior ET for MBC (no/<12m/=12m), visceral disease (yes/no), initial dose (<3,000/3,000/>3,000mg). Toxicities were typical of X monotherapy. X was continued for =12 months in 46 pts without cumulative toxicity. Conclusions: X appears highly active as first-line CT for MBC pts, including those who had received ET for MBC and/or adjuvant CT. Long-term treatment is well tolerated. The safety profile is consistent with previous reports. High activity, oral administration, lack of alopecia, and low hematologic toxicity make X a very attractive first- line CT for slowly progressing disease and/or after ET failure. No significant financial relationships to disclose.