Treatment effect of capecitabine and docetaxel or docetaxel alone by oestrogen receptor status in patients with metastatic breast cancer: Results of an exploratory analysis

This is the authors' abstract. We don't add key points for this paper.

We investigated treatment effects by oestrogen receptor (ER) status among women with metastatic breast cancer (MBC) receiving capecitabine (C) plus docetaxel (D) or D alone in a randomised phase III trial. Data were retrospectively analysed from patients whose disease had recurred following (neo)adjuvant anthracyclines. ER status was identified in 356/506 patients. In patients with ER-positive tumours, median overall survival from enrolment was 17.7 months with CD versus 12.5 months with D (hazard ratio [HR] 0.65, 95% confidence interval [CI]: 0.47-0.89; P = 0.007) and median time to progression (TTP) was 6.8 and 5.4 months, respectively (HR 0.62, 95% CI: 0.46-0.84; P = 0.002). For patients with ER-negative tumours, significantly longer TTP was seen with CD (5.2 versus 3.5 months; HR 0.73, 95% CI: 0.53-0.98; P = 0.038). Whether there is an additional C to D treatment benefit in ER-positive versus ER-negative MBC requires further evaluation.