NCT00754845

Letrozole in Breast Cancer Who Have Received 5 Years of Aromatase Inhibitor Therapy

A Double Blind Randomization to Letrozole or Placebo for Women Previously Diagnosed With Primary Breast Cancer Completing Five Years of Adjuvant Aromatase Inhibitor Either as Initial Therapy or After Tamoxifen (Including Those in The MA.17 Study)

• Status: Completed
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 1,918 (actual)
• Sponsor: Canadian Cancer Trials Group · Network
• Sex: Female
• Age: 0 Years – 120 Years
• Healthy volunteers: Not accepted

Summary

RATIONALE: Estrogen can cause the growth of breast cancer cells. Hormone therapy using letrozole may fight breast cancer by lowering the amount of estrogen the body makes. It is not yet known whether letrozole is more effective than a placebo in treating in women with breast cancer who have already received 5 years of aromatase inhibitor therapy. PURPOSE: This randomized phase III trial is studying letrozole to see how well it works compared with a placebo in treating women with primary breast cancer who have received 5 years of aromatase inhibitor therapy.

Detailed description

OBJECTIVES: Primary * To compare the disease-free survival of women with primary breast cancer treated with letrozole vs placebo after completing approximately 5 years (i.e., 4½ - 6 years) of aromatase inhibitor therapy (e.g., letrozole, anastrozole, or exemestane). Secondary * To compare the effect of these drugs on overall (all cause specific) mortality of these patients. * To compare the incidence of contralateral breast cancer in patients treated with these drugs. * To evaluate the long-term clinical and laboratory safety of aromatase inhibitor therapy, particularly cardiovascular morbidity and mortality (e.g., significant coronary artery disease, including myocardial infarction and angina requiring percutaneous transluminal coronary angioplasty or coronary artery bypass graft, fatal and nonfatal strokes, and all vascular deaths); incidence of all bone fractures (with particular emphasis on hip and wrist fractures as indicators of osteoporosis); changes in bone density; and common toxicities. * To compare overall quality of life (QOL) and menopausal-specific QOL of patients treated with these drugs. OUTLINE: This is a multicenter study. Patients are stratified according to lymph node status at diagnosis (negative vs positive vs unknown), prior adjuvant chemotherapy (yes vs no), interval between last dose of aromatase inhibitor therapy and study randomization (\< 6 months vs 6 months to 2 years), and duration of prior tamoxifen citrate use (0 vs \< 2 years vs 2 - 4½ years vs \> 4½ years). Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive oral letrozole once daily for up to 5 years in the absence of unacceptable toxicity, disease recurrence, or development of a second malignancy. * Arm II: Patients receive oral placebo once daily for up to 5 years in the absence of unacceptable toxicity, disease recurrence, or development of a second malignancy. Patients undergo bone mineral density measurement by DEXA scan at baseline (if not done within 12 months of study entry), at 24 and 48 months during study therapy, and at the completion of study therapy. Some patients also complete quality-of-life questionnaires at baseline and at 12, 24, 36, 48, and 60 months. After completion of study therapy, patients are followed annually.

Conditions

• Breast Cancer

Interventions

Type	Name	Description
DRUG	letrozole	Given orally
OTHER	placebo	Given orally

Timeline

• Start date: 2004-11-23
• Primary completion: 2015-12-21
• Completion: 2017-04-19
• First posted: 2008-09-18
• Last updated: 2023-08-25
• Results posted: 2018-11-19

Locations

43 sites across 2 countries: Canada, United Kingdom

Regulatory

• FDA-regulated drug study