FACT: an open-label randomized phase III study of fulvestrant and anastrozole in combination compared with anastrozole alone as first-line therapy for patients with receptor-positive postmenopausal breast cancer.

PURPOSE: To compare the effect of therapy with anastrozole versus a combination of fulvestrant and anastrozole in women in first relapse of endocrine-responsive breast cancer. PATIENTS AND METHODS: Postmenopausal women, or premenopausal women receiving a gonadotropin-releasing hormone agonist, with estrogen receptor- and/or progesterone receptor-positive disease at first relapse after primary treatment of localized disease were open-label randomly assigned to a fulvestrant loading dose (LD) regimen followed by monthly injection plus 1 mg of anastrozole daily or to 1 mg of anastrozole daily alone. The primary end point was time to progression (TTP). RESULTS: In all, 514 women were randomly assigned to fulvestrant plus anastrozole (experimental arm; n = 258) or anastrozole (standard arm; n = 256). Approximately two thirds had received adjuvant antiestrogens, but only eight individuals had received an aromatase inhibitor. Median TTP was 10.8 and 10.2 months in the experimental versus standard arm, respectively (hazard ratio [HR] = 0.99; 95% CI, 0.81 to 1.20; P = .91); median overall survival was 37.8 and 38.2 months, respectively (HR = 1.0; 95% CI, 0.76 to 1.32; P = 1.00). Incidences of prespecified adverse events (AEs) were similar. Hot flashes were more common in the experimental arm: 63 patients (24.6%) versus 35 patients (13.8%) in the standard arm (P = .0023). Death owing to AEs was reported in 11 (4.3%) and five patients (2.0%) in the experimental versus standard arm, respectively. CONCLUSION: Fulvestrant (250 mg + LD regimen) in combination with anastrozole offered no clinical efficacy advantage over anastrozole monotherapy in this population of individuals with a relatively high proportion of previous adjuvant antiestrogen exposure.

Clinically used breast cancer markers such as estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 are unstable throughout tumor progression.

PURPOSE To investigate whether hormonal receptors and human epidermal growth factor receptor 2 (HER2) change throughout tumor progression, because this may alter patient management. PATIENTS AND METHODS The study cohort included female patients with breast cancer in the Stockholm health care region who relapsed from January 1, 1997, to December 31, 2007. Either biochemical or immunohistochemical (IHC)/immunocytochemical (ICC) methods were used to determine estrogen receptor (ER), progesterone receptor (PR), and HER2 status, which was then confirmed by fluorescent in situ hybridization for IHC/ICC 2+ and 3+ status. Results ER (459 patients), PR (430 patients), and HER2 (104 patients) from both primary tumor and relapse were assessed, revealing a change in 32.4% (McNemar's test P < .001), 40.7% (P < .001), and 14.5% (P = .44) of patients, respectively. Assessment of ER (119 patients), PR (116 patients), and HER2 (32 patients) with multiple (from two to six) consecutive relapses showed an alteration in 33.6%, 32.0%, and 15.7% of patients, respectively. A statistically significant differential overall survival related to intraindividual ER and PR status in primary tumor and relapse (log-rank P < .001) was noted. In addition, women with ER-positive primary tumors that changed to ER-negative tumors had a significant 48% increased risk of death (hazard ratio, 1.48; 95% CI, 1.08 to 2.05) compared with women with stable ER-positive tumors. CONCLUSION Patients with breast cancer experience altered hormone receptor and HER2 status throughout tumor progression, possibly influenced by adjuvant therapies, which significantly influences survival. Hence, marker investigations at relapse may potentially improve patient management and survival.