Send to

Choose Destination
See comment in PubMed Commons below
J Clin Oncol. 2008 Apr 20;26(12):1956-64. doi: 10.1200/JCO.2007.12.6334. Epub 2008 Mar 10.

Efficacy, toxicity, and quality of life in older women with early-stage breast cancer treated with letrozole or placebo after 5 years of tamoxifen: NCIC CTG intergroup trial MA.17.

Author information

  • 1University of Vermont College of Medicine, 1 South Prospect St, Saint Joseph 3400, Burlington, VT 05401, USA.



National Cancer Institute of Canada Clinical Trials Group trial MA.17 randomly assigned 5,187 postmenopausal, hormone-receptor-positive patients with early breast cancer who completed 5 years of tamoxifen to receive either letrozole or placebo. At 30 months median follow-up, letrozole significantly improved disease-free survival (DFS) in all patients and overall survival (OS) in node-positive patients. Breast cancer incidence increases with age and more than 1,300 women age 70 years or older were enrolled onto MA.17, making it ideal to explore the benefits, toxicities, and quality of life (QOL) impact of letrozole on older women.


In this study, 5,169 randomly assigned patients were divided into three age groups: younger than 60 years (n = 2,152), 60 to 69 years (n = 1,694), and >or= 70 years (n = 1,323). Log-rank test was used to compare differences in DFS, distant-disease-free survival, and OS between age and treatment groups, and Cox models were used to estimate hazard ratios and associated 95% CIs. QOL was measured using the Medical Outcomes Short Form-36 and the Menopause-Specific Quality-of-Life questionnaire.


At 4 years, DFS demonstrated statistically significant differences favoring letrozole only in patients age younger than 60 years (hazard ratio = 0.46; P = .0004); there was no interaction between age and treatment, indicating a similar effect of letrozole among all age groups. There was no difference in toxicity or QOL at 24 months among letrozole- and placebo-treated patients age >or= 70 years.


Healthy patients age 70 years and older completing 5 years of tamoxifen should be considered for extended adjuvant therapy with letrozole.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Atypon
    Loading ...
    Support Center