Superior Efficacy of Letrozole Versus Tamoxifen as First-Line Therapy for Postmenopausal Women With Advanced Breast Cancer: Results of a Phase III Study of the International Letrozole Breast Cancer Group
- Study type
- Clinical trial
- Study name
- International Letrozole Breast Cancer Group
- Phase
- Phase 3
- Design
- Randomised comparative phase 3 trial (letrozole versus tamoxifen)
- Sample size
- 907 patients
- Source
- JCO · 2001
In plain words
In this large study, two hormone tablets were compared in postmenopausal women with advanced breast cancer: letrozole and tamoxifen. Letrozole kept the disease under control for longer (median about 41 weeks versus 26 weeks) and shrank the tumour in a larger share of patients. Both drugs were well tolerated. The choice of the right treatment should always be made with the treating doctor.
Key results
Treatment arms and regimens
Letrozole (oral aromatase inhibitor) 2.5 mg once daily (453 patients).
Tamoxifen 20 mg once daily (454 patients).
Source of the regimen details: Abstract of the paper
Doses are given for the information of specialists, as in this study’s protocol, and are not a prescription. Every drug must be prescribed by the treating physician for the individual patient.
Study population
Postmenopausal women with advanced breast cancer whose tumours were oestrogen receptor- and/or progesterone receptor-positive, or whose receptor status was unknown for both. Patients who had relapsed during or within 12 months of adjuvant anti-oestrogen therapy, or who had received prior hormone therapy for advanced disease, were excluded. One prior chemotherapy regimen for metastatic disease was allowed.
Endpoints
Primary endpoint: time to progression (TTP). Secondary endpoints: overall objective response rate (ORR) and its duration, rate and duration of clinical benefit, time to treatment failure (TTF), overall survival and tolerability.
Safety and side effects
Based on the abstract, both treatments were well tolerated. Details of adverse events (including grade ≥3 events) are not given in the abstract and are available in the full text of the paper.
Clinical significance and place in guidelines
Based on the abstract, the authors concluded that these findings support the use of letrozole as first-line hormone therapy in postmenopausal women with advanced breast cancer. The current status of this approach in treatment guidelines and drug approvals is not mentioned in the abstract and should be checked separately.
Limitations
Overall survival data were immature at publication and were not reported. The abstract gives no detailed information on grade ≥3 adverse events. The paper has an erratum (J Clin Oncol 2001;19:3302).
This summary was prepared by the editorial team from the published paper; the original paper is the final reference. Read the original abstract on PubMed.