FUL represents a ET option for pts whose endocrine sensitive locally or advanced breast cancer (LABC) has progressed after an antiestrogen. The 500 mg monthly represents the actual standard dose showing a disease control rate of 45%-72% and a progression free survival (PFS) ranging from 6.5 to 23 months (mo) depending on treatment line. To evaluate the efficacy of FUL in unselected LABC pts we performed an observational prospective trial.
Eligible pts were women with LABC suitable for ET and who received previous treatment with either an antiestrogen or an aromatase inhibitor (AI) as a first-line therapy, or relapsing while on or within 1 year from completion of adjuvant ET. Primary end point was the clinical benefit rate (CBR), defined as complete response (CR) or partial response (PR) plus stable disease (SD) lasting >24 weeks. Secondary end points were overall survival (OS), PFS and tolerability.
163 consecutive eligible pts were enrolled. Pts characteristics: median age 68 ys, PS 0/1 in 95% of pts, adjuvant ET administered in 75% of pts, 55% of pts had received first-line ET (11 tamoxifen, 78 AIs), 44% had visceral disease, 30% had bone disease, 52% of pts had more than one site of disease. Overall, CBR was reached in 59% of pts (CR + PR + SD, 95%CI 51-66). Median PFS was 7 mo (95%CI 6-8), median OS was 35 mo (95%CI 24-46). Analysis of safety did not show any relevant toxicity, no serious adverse event has been observed. In the multivariate analysis, visceral involvement showed to be prognostic factor for PFS (HR 1.60 95%CI 1.13-2.27, p 0.008), whereas previous ET in advanced setting (HR 2.11, 95%CI 1,27-3.29, p 0.004) and >1 site of metastases (HR 2.53 95%CI 1.54-4.22, p 50% (OR 3.49 95%CI 1.30-9.38, p 0.01), 1 site of metastases (OR 2.21 95%CI 1.08-4.50, p 0.03) and no previous ET for advanced disease (OR 2.24 95%CI 1.1-4.58, p 0.03) were predictive factors for CBR.
In this observational prospective trial, FUL showed to be a safe and active treatment and confirm the efficacy of the 500 mg dose. Treatment was very well tolerated. As expected, pts who had received first-line ET have a worse outcome and a reduced CBR.
Clinical trial identification
AUSL Viterbo Ethical committe approval for prospective observational trial nr 16889 CE 320/12, April 6 2012
Legal entity responsible for the study
All authors have declared no conflicts of interest.