Cognitive function in postmenopausal women receiving adjuvant letrozole or tamoxifen for breast cancer in the BIG 1-98 randomized trial

Kelly-Anne Phillips, Karin Ribi, Zhuoxin Sun, Alisa Stephens, Alastair Thompson, Vernon Harvey, Beat Thuerlimann, Fatima Cardoso, Olivia Pagani, Alan S. Coates, Aron Goldhirsch, Karen N. Price, Richard D. Gelber, Juerg Bernhard

    Research output: Contribution to journalArticlepeer-review

    60 Citations (Scopus)


    Cognitive function in postmenopausal women receiving letrozole or tamoxifen as adjuvant endocrine treatment was compared during the fifth year of treatment in a substudy of the BIG 1-98 trial. In BIG 1-98 patients were randomized to receive adjuvant (A) 5-years tamoxifen, (B) 5-years letrozole, (C) 2-years tamoxifen followed by 3-years letrozole, or (D) 2-years letrozole followed by 3-years tamoxifen. The primary comparison was the difference in composite score for patients taking letrozole (B + C: N = 65) vs. tamoxifen (A + D; N = 55). The patients taking letrozole had better overall cognitive function than those taking tamoxifen (difference in mean composite z-scores = 0.28, P = 0.04, 95% Cl: 0.02, 0.54, Cohen's D = 0.40 indicating small to moderate effect). In this substudy, breast cancer patients taking adjuvant letrozole during the fifth year of treatment had better cognitive function than those taking tamoxifen, suggesting aromatase inhibitors do not adversely impact cognition compared with tamoxifen. (C) 2010 Elsevier Ltd. All rights reserved.

    Original languageEnglish
    Pages (from-to)388-395
    Number of pages8
    Issue number5
    Publication statusPublished - Oct 2010


    • Cognitive function
    • Breast cancer
    • Aromatase inhibitor
    • Tamoxifen
    • Letrozole
    • Quality of life
    • MEMORY
    • BRAIN
    • RATS

    Cite this