Meta-analyses of phase 3 randomised controlled trials of third generation aromatase inhibitors versus tamoxifen as first-line endocrine therapy in postmenopausal women with hormone receptor-positive advanced breast cancer.

BACKGROUND: Four randomised controlled trials (RCTs) in postmenopausal women with advanced breast cancer (ABC) comparing aromatase inhibitors (AIs) versus the selective estrogen receptor modulator tamoxifen, each individually reported significantly longer progression-free survival (PFS) but none showed a significant difference in overall survival (OS). In these trials between 6.8% and 55% of tumours were hormone receptor (HR) status unknown or negative. This meta-analysis restricted the comparison to HR-positive (HR+) tumours. METHODS: Anonymised individual patient data were obtained from three RCTs, EORTC (exemestane versus tamoxifen), Study 0027 and Study 0030 (both anastrozole versus tamoxifen). For the remaining RCT (Femara Study PO25; letrozole versus tamoxifen), odds ratio (OR) or hazard ratio (HzR), with confidence intervals were obtained from the clinical study report, for patients with HR+ tumours, in addition to published data. In total, data were obtained from 2296 patients; 1560 (68%) had HR+ ABC. FINDINGS: The OR for clinical benefit rate was 1.56, in favour of AIs (p < 0.001). The duration of clinical benefit was not significantly increased by AIs (HzR 0·88; p = 0.08). For PFS the HzR (0.82) was in favour of AIs (p = 0·007). However, for OS the HzR (1.05) was not significantly different between AIs and tamoxifen (p = 0.42). INTERPRETATION: Although third generation AIs put significantly more patients into 'clinical benefit', their tumours were not controlled for significantly longer. Overall, while this resulted in a significantly greater PFS in favour of the AIs, this did not translate into improvement in OS.

Meta-analyses of visceral versus non-visceral metastatic hormone receptor-positive breast cancer treated by endocrine monotherapies.

Endocrine therapy (ET) is recommended as first-line therapy for the majority of patients with hormone receptor-positive (HR+), human epidermal growth factor 2-negative advanced breast cancer (ABC); however, the efficacy of ET in patients with visceral metastases (VM) versus patients whose disease is limited to non-visceral metastases (non-VM) is debated. Meta-analyses including available data from randomised controlled trials of first- and second-line endocrine monotherapies for patients with HR+ ABC were performed to address this question. In one and two-stage meta-analyses, progression-free survival (PFS), overall survival (OS), clinical benefit rate (CBR) and duration of clinical benefit (DoCB) outcomes were analysed. In the first-line meta-analysis (seven trials; n = 1988) tamoxifen and fulvestrant significantly improved PFS, OS and CBR for patients with non-VM versus those whose disease included VM. The most substantial hazard ratios were observed for fulvestrant 500 mg; 0.56 (95% confidence interval [CI] 0.45-0.70) and 0.55 (95% CI 0.42-0.72) for PFS and OS, respectively. In the second-line meta-analysis (seven trials; n = 2324), all ET combined was more effective (in terms of PFS, OS and DoCB) for non-VM versus VM. In both meta-analyses, patients with non-liver VM had better clinical outcomes than patients with liver VM for all types of ET. Patients whose disease included non-VM sites had better clinical outcomes with endocrine monotherapy compared with patients whose disease included VM. These findings may facilitate better informed treatment decision-making.

First-line vs second-line fulvestrant for hormone receptor-positive advanced breast cancer: A post-hoc analysis of the CONFIRM study.

OBJECTIVES: The double-blind, phase III CONFIRM study (NCT00099437) evaluated fulvestrant 500 mg vs fulvestrant 250 mg in postmenopausal women with hormone receptor-positive locally advanced/metastatic breast cancer (LA/MBC). This post-hoc analysis investigated the efficacy and safety of fulvestrant given either first-line or second-line for advanced disease. MATERIALS & METHODS: Progression-free survival (PFS) and overall survival (OS) with fulvestrant 500 mg vs fulvestrant 250 mg was evaluated using unadjusted log-rank tests in patients treated in the first- (progression during or within 12 months after completing adjuvant endocrine therapy; n = 387) and second-line (following endocrine therapy for LA/MBC; n = 343) settings. RESULTS: First-line fulvestrant 500 mg significantly prolonged PFS vs fulvestrant 250 mg (median PFS 5.6 vs 4.2 months; hazard ratio [HR] 0.80; 95% confidence interval [CI] 0.64-1.00; p = .047). Median PFS was numerically greater with second-line fulvestrant 500 mg vs fulvestrant 250 mg (7.9 vs 6.3 months; HR 0.80; 95% CI 0.64-1.02; p = .068). At data cut-off (75.5% maturity), median OS with first-line fulvestrant 500 mg was 23.2 vs 22.1 months with fulvestrant 250 mg (HR 0.87; 95% CI 0.70-1.10; p = .251), and 29.2 vs 22.8 months, respectively, in the second-line (HR 0.75; 95% CI 0.58-0.96; p = .020). The safety profile was broadly comparable between dose groups and across treatment lines, and consistent with the overall patient population. CONCLUSION: The superiority of fulvestrant 500 mg over fulvestrant 250 mg in patients with LA/MBC in CONFIRM was consistent in both the first- and second-line settings for PFS, and numerically greater in both settings for OS.

Health-related quality of life from the FALCON phase III randomised trial of fulvestrant 500 mg versus anastrozole for hormone receptor-positive advanced breast cancer.

BACKGROUND: The phase III randomised FALCON trial (NCT01602380) demonstrated improved progression-free survival with fulvestrant 500 mg versus anastrozole 1 mg in endocrine therapy-naïve postmenopausal women with hormone receptor-positive (HR+) locally advanced or metastatic breast cancer (LA/MBC). Furthermore, overall health-related quality of life (HRQoL) was maintained and comparable for fulvestrant and anastrozole. Here, we present additional analyses of patient-reported HRQoL outcomes from FALCON. METHODS: Women with endocrine therapy-naïve HR+ LA/MBC were randomised 1:1 to fulvestrant (days 0, 14, 28, then every 28 d) or anastrozole (daily) until disease progression or discontinuation. HRQoL was assessed by FACT-B questionnaire (TOI and FACT-B total score) at randomisation and every 12 weeks during treatment. HRQoL data post-treatment (with or without progression) were also collected. RESULTS: In total, 462 patients were randomised (fulvestrant, n = 230; anastrozole, n = 232). Compliance to FACT-B overall ranged from 60.0 to 97.4%. Mean change from baseline in TOI and FACT-B total score remained broadly stable (approximately ± 3 points to week 132) and was similar between arms during treatment. HRQoL was also maintained in FACT-B subscales. Approximately one-third of patients had improved TOI (≥+6 points) and FACT-B (≥+8 points) total scores from baseline up to week 120 and 132, respectively, of treatment with fulvestrant (ranges 26.4-45.0% and 22.4-35.8%, respectively) and anastrozole (ranges 18.6-32.9%, and 22.7-37.9%, respectively). CONCLUSIONS: Mean change from baseline in TOI and FACT-B total score was maintained for fulvestrant and anastrozole; similar proportions of patients in both arms had improved TOI and FACT-B total scores. CLINICALTRIALS. GOV IDENTIFIER: NCT01602380.