CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 5,187 enrolled
Drug / intervention
letrozole +1 moredrug
Likely dose
Not stated in record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT00003140
NCT00003140Phase 3Completed
CompareCT.gov

A Phase III Randomized Double Blind Study of Letrozole Versus Placebo in Women With Primary Breast Cancer Completing Five or More Years of Adjuvant Tamoxifen

NCIC Clinical Trials Group·interventional·Posted Jan 27, 2003·Updated Mar 27, 2026

In Brief

A Phase 3 clinical trial evaluating letrozole and placebo for Breast Cancer. Completed, enrolled 5,187 participants across 57 sites in 2 countries.

Detailed Summary

RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using letrozole may fight breast cancer by reducing the production of estrogen. PURPOSE: This randomized phase III trial is studying letrozole to see how well it works in treating women with breast cancer who have received tamoxifen for at least 5 years.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
ConditionsBreast Cancer
CountriesCanada, United Kingdom
CollaboratorsNational Cancer Institute (NCI), North Central Cancer Treatment Group, ETOP IBCSG Partners Foundation, Eastern Cooperative Oncology Group, SWOG Cancer Research Network, Cancer and Leukemia Group B, European Organisation for Research and Treatment of Cancer - EORTC

Timeline

Phase 3CompletedFinished
199819992000200120022003200420052006200720082009201020112012201320142015201620172018201920202021202220232024202520262027
First PostedJan 27, 2003
Enrollment StartAug 24, 1998
Primary CompletionAug 22, 2003
Study CompletionOct 1, 2003
TodayJul 2, 2026
Enrollment to primary: 5.0 yearsPosted 23.4 years ago

Interventions

letrozoledrug

Given orally

placeboother

Given orally